I've cruised the Felt replacement parts pages a bit trying to see which newer parts would work on my older DA.
It looks to me over time that they've made a little lower "inset" into the frame at the headset where the fork comes in and the integrated rotating stem mount thing goes.
Meaning, I don't think my older DA can do it. Yours might. Looking at their replacement parts pages, the geometry of the stems in that mounting point look similar. Might be worth exploring. It already ended I think, but there was a used Bayonet 4 fork on Ebay recently for like $250.
As for the fit overall? I have to feign ignorance. I post a lot on Slowtwitch and got lucky and had a local fitter and an accomplished tri/TT racer comment on my earlier videos and I made adjustments accordingly. I basically knew I was young enough or flexy enough to get into most TT positions, so I watched tunnel videos and old topics finding something to copy. Copying someone in aero isn't always good, people are different. But, I emulated golf swings growing up as I was too "middle class" to afford lessons. So I'd video myself then find a pro with a "close enough" swing style in the magazine fold outs from Golf Digest, then adjust accordingly.
Same on the bike so far. I can emulate a fast rider, try it out on-road a few times, run some Chung data on it.......then try again.
Given that.......not sure the crank size, but that's a cheat to be able to raise the saddle if you want. If you're on 175's or 172.5's and go to 170 or 165mm, that's not 1:1 for raising the saddle......but you can raise it some of that. That would bring the hind end up and back more level.
Again, not an expert, that's just how I'd do it outside of using a basebar that would allow it.
Also, if you're within any rules you might have to abide by.........if you think of the legs of a triangle, the longer your reach the lower your shoulders/head will be. I'm guessing that's why the UCI dictates the "angle" rule for your arms. Also my guess to why they have the max height of skis above pads, cause you're rotating the triangle to get lower while keeping the angle "allowable".
I'd try the basebar with minimal stack first, and maybe cranks if that isn't too much a pain to swap between for a TT versus road. I'm guessing you must run Di2 to swap those over from road to TT.
I found this: recommending a Felt Devox in this topic for lowest stack base bar
https://forum.slowtwitch.com/forum/S...s%3F_P4481022/