Skipping any discussion of rationality, because that is for you to have with a qualified professional, not BF.
1) Ultegra 8100 Di2 is legitimately the best shifting drivetrain I've ever ridden. The synchro shifting is fast and precise. Massive improvement over the prior generation 11-speed drivetrain.
2) While the ARC1650 branding of the wheels is NOT on DT Swiss' website, they look like ARC 1400. If they are, they are absolutely TL ready and will almost certainly be taped from the factory, juts slap a TL valve stem on, mount the tires and go.
3) PMs are easily sourced these days...