Non-destructive scene background image swapping
(disclaimer: I'm using "map size" === canvas/scene size without the buffer zone)
Switching the scene background image changes map size.
Problem: When selecting a new background image, the map size text field does not immediately adjust, giving the impression that map size won't be affected. However upon scene save, the map size does change to the size of the chosen image, moving scene assets out of position if image size of the previous image is not the same.
Example: Switching a map to a different version (sunny, rainy, haunted, etc.) when the image had to be stretched to match the grid. Replacing the image reduces map size, pushing many scene assets out of position. Very frustrating mid-session or worse, mid-encounter.
Suggestion: There should be an indication (text field) of the map size, an indication of the size of the chosen image, and a button to adjust the map size to the image dimensions. This gives the user control over when the map size changes. By default, the background image should resize to the map, not the other way round, unless triggered on purpose.
Additional control and transparency, reduced risk of damaging scene setups and generally reducing surprise effects.
Low/medium priority. It has worked well so far, but can cause nasty interruptions in a session when it goes wrong.