So I guess save are not compatible between various versions of games, especially FFA/MQ and SoM but maybe SD3 even if they're all based on the Japanese ROM?
Since they're the proper original ROMs (except for German SoM but we don't know what's changed in the new ROM right) I guess every version of SoM runs in PAL 50Hz (slower), but the English one's actually using the US ROM so it's full speed at 60Hz?
Last technical question as I couldn't find the info: is the collection actually 1080p when docked? It'd be interesting as SoM on SNES Mini is limited to the console's 720p output.