So faced with a choice between AbsoluteBlack, FSA, Sugino or Praxis, you've found problems with each one. Well done, you've discovered how kit choice works. Shimano will probably follow the trend in a couple of years but until then you'll have to stop being sniffy about Tiagra, triples, square taper BBs and/or mechanical shifting.
AbsoluteBlack - Oval rings, still not sure about them, but most plausible option out there
FSA - Only works with their own BB, but it's external bearing, offers two price options. Plausible
Sugino - Discontinued, available in a few places, but 300 quid a go, and not sure about replacement parts, because it's discontinued
Praxis - Unless I'm missing something, I can't find anything smaller than 32/48. That's not 30/46...
I'd like Di2 shifting so I can have shifters in multiple places, (see other threads for more discussion about this). I currently run Tiagra 2x10 (With a MTB front mech and chainset, that shimano says doesn't work).
But of all the options listed, only the AbsoluteBlack oval rings provide an easy drop in replacement for the chainrings on an off the peg bike. I've yet to get my head round the pros and cons of oval chain rings. it's also worth noting that the Absolute Black rings are not compatible with most crank based power meters, they are updating the design to be compatible with the Dura Ace Shimano Power meter, but that's the only crank based option, according to AbsoluteBlack themselves.
(While we're at it, I'd love it if manufacturers still made 8 speed brifters. You know what though? I realise I'm in a minority.)
I know I'm in a minority, but I also know that this minority isn't as small as some may think (look at the number of gravel bike riders who ask for sub compact chainsets.
When I finish building my Di2 bike, I'm wondering if I can somehow set it up to log which gear I'm in at any given time on a ride so I can get an idea on how much I'm using each gear...
J