i like the 4iiii products. my aethos came with the precision pro, which was the dual sided predecessor to the precision 3+. i later purchased just a left side precision 3+ for my scott addict rc eride, and recently pulled that crank (the same dura ace 12 speed crank and rings as the aethos came with) and sent it to 4iii to get the right side added. i put the 34t little ring on that one, so now i have one with 52-34 and the precision 3+ dual side, and the other 52-36 with the older precision pro dual side.

my comments on the 4iii stuff in general is - great, but not perfect. the pairing has been occasionally glitchy, and i have had an issue with the older one where the battery cover cap cracked due to incompatibility between their plastics and the kind of cleaners people use on drivetrains these days. a well documented issue, and they were very responsive to tech support when needed. the process of getting the crank upgraded is a little slow, they're in canada, but it all went smoothly.

i probably would not recommend the 52-34 combo to anyone who is really finicky about shift quality, the da 12 speed front der shifts it, but maybe once every 4-5 shifts it takes a rotation or two to get over on the shift from little to big. big to little shifts same as before, rd shifts still instant and smooth as before. i'll probably switch the big ring to 50t on that bike when i see those rings on sale, they're kinda overpriced.

the 5.6% difference between 36-34 and 34-34 is in fact noticeable for me. i'm climbing in the low 80s instead of the high 70s. i like it. i'm certain your power to weight ratio is way higher than mine, so your mileage may vary!