It would be nice for there to be an area in settings or maybe in the grid styles area where a user can create margins for each Frame separately, depending on which frame is selected. Then, once the margins are created, allow the user to copy and paste the margins between Frames… Or alternatively allow a style to be created from the created margins… similar to grids and columns.
I understand that a user can achieve something very similar with ruler guides. But I think having an additional margin creation feature would allow that much more design options for those who work that way.
The option to create these margins might be created here: