LightCarbon just updated their TT frame on their website to the new LCTT25.

Features both built in hydration and storage which is a huge plus compared to a lot of the others frames in the same pricebracket. It also has a UDH hanger. Cockpit seems really nice and customizable too.
Sadly the maximum tire size is 28c which seems really outdated when more and more frames make space for 30c and 32c nowadays.

https://www.lightcarbon.com/lightcarbon-ultra-aero-triathlon-carbon-frame-disc-brake-700c-carbon-fiber-tt-bike-frameset_p267.html

Got quoted 1450USD for matte black frame.

28C is outdated indeed.
Surprisingly, triathletes are very old fashioned when it comes to tyre size. I guess they will evolve eventually, comfort is speed, especially on long distances.

Given how the Shiv looks, specialized says that unless you're doing Kona (notorious for brutal side winds), choosing a frame that's tube depth maxxing is not be a blessing. I dont like Specialized, but they do seem to have competent engineers.

The reach on this seems low. The T47 and UDH are nice, but the 28mm tires and scrunched up geometry are behind the times.

I'm not super keen on built in hydration. Built in storage for spares/tools is nice, but some standard bottles work just fine BTA or BTS.

Yep, the reach seems on the low end especially when it's more common to be in a more stretched position nowadays. Funnily enough it fits perfectly to what my fitter recommends

The space for the bladder could possibly be used for storage too, and for the price you really get a lot of extra features compared to other frames. It just seems to fit in a weird spot in the more modern lineup of triathlon frames when it's behind on tire clearance and geometry.

What do the wind tunnel tests say about these barn door frames specifically? I feel like an aero road bike can get you in the TT position with the right bars while having more tire clearance and less weight. TT frames seem mainly like an aesthetic choice these days.

TT bikes are a bitch in sidewinds as well, modern aerobikes can probably double as both much better without giving up too much overall, but being much more versatile.