Happy Holidays!
Joe from chinacycling hinted that all ltwoo groupsets were compatible with each other, despite a previous claim they weren't. I'm sure somebody here has both eGR and a road groupset. Can you confirm the eGR RD can be paired with eRX shifters?
I checked it for you, mounted rear derailleur eGR front eR9 works together, gear change works RD reacts to the right brake lever FD reacts to the left brake lever so the sets can be swapped. A large beer is due