My first test display, an Xgimi beamer seems to be very relaxed about missing or wrong HDMI info frames which made it work with only the timing changes.
While I was testing with my LG 3D TV, I realized that it didn’t switch to 3D with any input format. I’ve added two more patches to the PR, one fixes TAB/SBS modeswitching and the other one takes care of FP. Now 3D works on three tested displays with the four commits of my PR.