I think you are asking about single mold frame or a one piece mold rather than monocoque? Monocoque means that the load bearing structure is a "single shell" its the equivalent of a unibody in auto design. That doesn't mean its not made of joined parts. The notion of a "true monocoque frame" or "full monocoque" to mean a frame that comes out of single mold is only something I have heard with relation to bikes, but right now it's a production method does not yet tangible benefit to consumers. Maybe there is a future cost benefit as layups become automated or maybe it allows for the use of lower grade materials to make bikes that are closer in weight to top frames?

Theoretically the lack of joints should mean a lighter frame at the same strength with greater freedom of design when it comes to layup design. The reality is that the joints are often made stronger than the tubes to ensure there isnt a failure and the use of smaller molds or doing it in sections still allows for greater control of the local area. As far as I know, none of the high performance road bikes or MTBs raced at the World Tour or World Cup level use a single piece manufacturing method as the tradeoffs in terms of getting the right compaction, etc don't yet produce the lightest or stiffest frames.

I don't think the Speeder is the same at the Hygge.

Back in the day there were only 2-3 carbon factories selling open molds. Flybike is one that still exists and seem to sell primarily through Carbonda. There was a factory called Gotobike which owns or owned the trademark for the Winspace name. Make what you will of that--but trying untangle who makes what frame and who designed what is, in my opinion not that useful. The relevant thing is whether or not you trust the brand to work with you and whether or not you think the combination of product quality and support will meet your needs.

What i do know is that I've been really happy with Speeder sourced parts and they sell a lot of parts, particularly forks. If I were to look for a partner to coordinate manufacturing and finalize design for a carbon bike part, Speeder would be part of the first outreach. However, they are primarily going to be more of a B2B type transaction while Tavelo appears to be investing quite a bit into the people and infrastructure to support consumers.

I have no idea if Speeder make their own bikes, their business arrangement with the factory or even if the frames and other parts come from the same factory. I THINK their new bike looks like an Adapt design and other than a bit more tire clearance and the bb86 spec looks pretty nice.

I use the couplers from Zeno. I have a set on my two main bikes. It allows me to remove the bars completely to inspect the forks.

They are also the ones currently used by No 22. I dont think you are in the US, but we also have a distributor here now: https://www.ticycles.com/components/hydraulic-brake-line-coupler-2m7fy.

They are functionally the same as the hydraulic ball valve type couplers that used for motorcycles and other industrial applications. The pins are a bit finicky but they are the most compact ones available. I don't think this solves your ask though. If you have enough slack to pull these out of an integrated bar stem you have enough slack to just pull the bars off.

That engraved lucky cat is fantastic.

bolded part is all industry marketing mumbo jumbo.  second part is true, but the main thing is about reducing deflection of the front wheel due to riding surface, wind, or manhandling the bike at high power out of the saddle and increasing stability at speed.  taller, heavier riders need this more, not less than smaller riders.

increasing reach (and thus FC) will only increase stability a bit - as it'll be a smaller amount and head angles would still be far too steep.

from a fit, bike handling and geometry perspective there is absolutely no reason for larger frames to have  steeper head angles.  whilst there's plenty for them to have slacker head angles.  the status quo is purely about package size.

also any further increases in reach are going to need increases in seat angle - they're already far too slack in larger sizes.

No, the bolded part is physics. Of course you can change other parts to the design to offset it (like lowering the rider). Fit and physics are often at odds in bike designs yet dependent on each other. Its a pretty hard thing to get right.

Seems nice. Geometry and everything seems like a pretty conservative design, but thats not a bad thing. I do like the shape of the frame as it feels like a blend between the Tavelo Attack and Arow. I also think its an Adapt design. Maybe this one: https://www.facebook.com/photo/?fbid=841101518026184&set=a.227485472721128
 

Speeder seems to get pretty good reviews on here and the SC-ADV09 Bikepacking / Gravel fork is used by quite a few higher end builder as the lower cost fork option offered alongside Enve.

For racing with narrow bars on maintained gravel roads, something like a BMC Kaius is ideal IMO. I don't think there are any open molds with a comparable geometry.

If you do a lot of single track and fire roads with a lot of elevation the SC Stigmata is probably a great choice, assuming it fits you. That slack HTA works, but it can also be annoying unless you have wider bars. I think there are some new open molds that are more like this. I think the Carbonda 707 and the new elastomer suspension Light Carbon bike are more like this.

For an allrounder, I get while the Canyon Grail and Trek Checkpoint are popular options. I think a bike like the Carbonda 696 is also this kind of bike, though I have never owned one. I think most people are best off getting a bike that is this kind of geometry, sort of half way to a race bike but slightly relaxed and designed for a more upright position.

However, gravel bike geometry is pretty fraught with tradeoffs and compromises, so the question is really hard to generalize an answer for. Even if the frames can fit wider tires, unlike on the road, toe overlap can be a very consequential issue  when racing. With 165mm cranks, my max tire size is 700c x 42mm treaded tired with a FC <610mm. Realistically, I personally would be conservative and go with a 40mm tire to be safe. That means that for me, most racing or allrounder bikes are pretty much limited to relatively narrow tires unless they can take 650b / 27.5" tires at which point, I want something like a 2.1" tire so the handling doesn't feel too quick as a result of the overall tire / wheel being too small. Given that the 650b tire size is dying and the remaining 27.5" tires are XC tires that are quickly becoming only available in 2.2"-2.4" there are no allrounder options that meet my needs.

The ideal solution is to buy two bikes, which is what brands like Enve want me to do. One for racing on 40mm tires and the other an ultra / trail focused rig that clears 700x50mm. The other option, which i did, was to go custom geometry allowing me to just barely get what I want without having to make these specific compromises.

I am guessing that the domestic market price is probably realistic for making and selling higher end frames right now. I doubt anyone is making a ton of money here, but they are all taking their piece.

The result might be that high end catalog frames like these don't make a ton of sense, and these brands might as well raise the price a couple hundred USD and do the full development, like the Seka Spear RDC which isnt that much cheaper than the European price for the Van Rysel RCR Pro frameset.