[Oz Cello]

Having each library remember its most recent sync file path would work well for me. Loading the sync folders takes a bit of time on my devices (~5s maybe) so when it's loading the wrong one when it first opens I have to wait until it's finished loading before I can go up a level and choose the right one. Choosing the right folder from the level up is much quicker because you can just long-press it to select it without having to open it first. Because of that the other good option for me would be for the sync file picker to always go to the folder that contains the folders for all the various library syncs but I imagine that would be much harder to do so remembering the path for each library would be great.
Guy