Apologies if my info is incorrect but I got it from Photography Stack Exchange, which states "The Godox XProC will work fine, but you will need a Godox X1R-C receiver to attach to the 580EXII hotshoe." also from the same answer "The 580EXII, however,...
I have a Canon R5 and a 580EX II speedlite which are incompatible. I have a Godox XproC V1 trigger and of course the 580 still wont fire. I now have a X1R C receiver that sits under my 580 speedlite and Voila I now have a working system. I also have...
1st curtain also works. Agreed that electronic will not fire flash. I also was surprised to find the 580ex-ii on my R5 will fire my Yongnuo YN460-ii flashes when in they are in slave mode. I have 2 of them.