I just posted a report of upgrading my 105 R7000 crankset and FD to GRX 600 46/30 in the Bicycle Mechanics sub-forum. So far things are working well, but I've only put about 5 miles on the bike so far. There replacement and setup process are pretty straightforward. I like the new gearing so far and seem to be using the big ring now as my primary chainring. I got my parts from BikeTiresDirect in Portland.
Did you have a compatibly issue with the front Derailleur or were you using the GRX front Derailleur for another reason ?
Thanks !