I can't help with the new crank selection but I can offer what I found through trial and error, that the front derailleur can't be angled with oval rings. The cage has to be parallel with the rings but even so, there will be some rub especially with larger range cassettes used for gravel. It isn't perfect on my bike but I am running an 11/42 MTB cassette.
Oval rings feel great to pedal but I'm having a bit of knee pain after switching to the oval rings. I've also resumed trail running so it is not possible to say which is causing the pain. Either way, I'm interested in the GRX 810 because of the higher geared 48 ring vs the 46 Absolute Black ring on my bike now. Going from stock Ultegra 50/34 to Absolute Black 46/30 has been great for bikepacking with a heavy load but I'm definitely slower on shorter, unloaded rides. The 48/31 should split the difference and give me back some speed and rub less.
GRX changes the chainline, no? Does anyone know if this requires the GRX front derailleur to be used or if an Ultegra FD will work?
I've seen the Praxis on a Trail Donkey 3.0 but can't offer any advice.
Please let us know what you decide on and how it works out. I'm interested in your experience and how it pans out.
-Tim-