Simple feature suggestion. Add a swap X/Y (or perhaps R/A or A/R) button in the grey bar at the bottom that allow me to swap the Active and Reference photo when in Reference view. Sometimes I select my reference photo and then open an image in Reference view and I think "hmm, I actually prefer the active one over the reference one", and at that point I want to swap them and alter the reference photo instead. Currently, I have to come out of develop view, re-set the reference photo and then click on the other image again. It would be so much easier if there was a swap button at the bottom like the Library side by side view has. Another use case is that I have my reference photo on the left and make tweaks to the active photo on the right, but then I take things a bit further and think, "hmm, now I want to add that change to the reference photo". I know some people may dismiss this and say "reference means that it's the one you're trying to match to, so you shouldn't be able to change it". I disagree. Sometimes editing is a process of continual tweaking and LR needs to enable that in an easy way.