What setup do you use exactly? I know SP Cycle has a cockpit where the bottom is open, so that should work, for example, but beyond that...
Very interested in setups that allow easy enough plane travel.

Anything semi-internal packs easily by removing the stem+handle bar and placing the bar sideways in the box. No need to disconnect any cables or hoses. I always get a used bike box from the LBS. You can either get them free or dirt cheap (like $10 USD or less). In the US, Alaska Airlines waives all fees for bike boxes (non e-bike) of any size and weight. They're my go-to airline for bike travel. The  only packing issue I've faced is with disc wheels. With center lock rotors, I've had to remove them to fit them in the box. Though I recently switched to 6-bolt disc wheels for my gravel bike. Hopefully I can fit them without having to remove the bolts. I also use bubble wrap and wrap every section of the bike and wheel hubs of the bike. You can also use spare bike bibs/jerseys in a bag as padding in the box.

Last bike I transported was an alloy gravel frame I gifted to a family member and total weight with box + a bunch of stuff in the box came out to to just under 15kg or 33 lbs.

I carry a spare CR2032 and taped to it is a larger coin (Quarter)  At least on my Wheeltop EDS levers, a coin works better to open the battery cover than a screwdriver.

LTwoo wireless shifters use tiny screws for the battery holder, so a tiny screwdriver is needed.

Luckily the screwdriver probably weighs only like 3 grams.

Need a 2nd saddle, shape would probably fit me but quality looks pretty questionable, any real world feedback?

I haven’t tried this Goldix saddle, but I do have 3 Ryet/Lexon saddles that work well. For me, the big advantage with 3D printed saddles is the minimal friction when shifting seated positions and they stay cool even in direct sun light. It’s a choice item, at least in the US it’s an easy return since the distribution warehouse is in California.

Chirping in as someone who's had their ER9 since August.

done 4000+km, mostly dry riding with the occasional wet ride and it's given me no major issues.
I have shrink wrapped the RD plug and left the FD plug as is, regularly hose down the bike during the wash process and stood up to it just fine.

Only complaint so far is not being able to see the shifter battery level in the app.
I've had the right shifter battery go flat on me ~3000km? so had to change the RD shifting to the left shifter through the app, very handy.

Groupset is also fairly light with the Giant TCR in a M/L weighing in at 7.3kg without pedals. I'd say this groupset provides decent value during the aliexpress discount seasons.

I'm going to give the heat shrink a try. I only clean my bike with a wet cloth and I don't ride in the rain. I carry spare CR2032 batteries in my saddle bag, plus a small screwdriver just in case my shifter batteries die out.

For some reason my hyperlink to a YouTube video showing up the new L-TWOO eRX 'Blue' edition update did not go through.

https://velo.outsideonline.com/road/road-gear/l-twoo-drivetrains-taipei-2024/

Also, why is LTWOO charging 100$ more for the option "with box". Is the version without box used in any way?

Without box version is smaller, with all items bubble wrapped. I guess it's easier and cheaper for the vendors to ship it that way.

Someone built the BXT 145. Weight and build issues in the YT comments (will need to translate).

https://youtu.be/ZmqFlPDVYlc?feature=shared

I received my first Wheeltop "Pre-order"  E-mail yesterday.   The prices are listed in Euros.  At the bottom of the email is a USA address: (No phone number)

Wheeltop
820 N River St. Portland, Oregon
97227
United States.

Looks like Wheeltop has a USA presence

Interesting choice to setup shop in Portland. They'll definitely be testing their groupset water proofing there (rains a lot). Great city for cycling and especially gravel!

Magene P505 power meter spider for like $250 USD if you add a chainring (or a few small items) to activate the $50 USD coupon:

https://www.aliexpress.us/item/3256804198593414.html