Hi all - so lots of great input and questions.
As to what I'm looking for and why not just buy a second set of wheels for the UP: I want to be sure to have a second bike as a backup bike but also a dedicated trainer bike for the winter months.
I'm enamored with the UP but I don't want to just buy another UP, I'd like to find something that is similarly relaxed in terms of riding position. My current "second bike" is a Canyon Ultimate CF SLX 9.0 which I find too twitchy, unreliable on imperfect surfaces, and frankly I'm only able to extract the additional performance ceiling of that bike in perfect, ideal conditions (no crosswind, good pavement, etc) which is a rarity where I live. My average speeds in Strava between the two bikes is incredibly close which I also find very confusing as I'd expect the Canyon to smoke my UP.
I originally went with the Ultimate as I thought endurance bikes had too much overlap with the UP but the reality is that I just simply don't like the Ultimate and would prefer the looks, feel, comfort, and approachability of the UP to the Canyon, 9 times out of 10.