Pixelmator needs a way to save a workspace which would remember what palettes are open and where they reside on your display.
I am now using a MacBook Pro with an external display and the palettes almost seem to randomize. They wont remain in the same spot if a quit the app and reopen. Having multiple saved workspaces on for MacBook Pro display only, one for multiple displays and maybe another for full screen would be great.
This is the number 1 feature missing from Pixelmator and really puts it behind Affinity Photo.