I used to run 175 on a giant propel bike i rigget as a TT bike. I'm now on 170, and considering 165. I probably wouldn't go shorter, i'm tall w long legs. My point: is the 175 a choice? You're probably going to have your knees come up to your chest in tuck, it's likely  going to cost you a F*** ton of watts. You'll still go watts, mind you, but chances are, your FTP in tuck vs your FTP upright on a bike is going to be massively different.

Very curious about the front end, because uncertainties there is the key reason why i still dont feel comfortable ordering a TT bike. Front end has to fit like a glove, or you're leaving a lot of speed & comfort on the table.

Doneeee. Took longer than expected as I fiddled a lot with the cockpit. Very happy overall but the list of wanted/unnecessary updates is long