When the icon file format was a dropdown on the top bar (it’s recently moved to the right-panel, which seems an odd place for it) I’m sure it used to retain the last-used image file format and size. I’ve checked the PC Pichon and it retains the setting, but on the new Mac Pichon, every time you restart the app, it defaults back to PNG 48px.
This isn’t helpful as I only ever use SVG, so I have several clicks added to my workflow, plus sometimes I forget, so I drag an icon into my design app and realise it is a bitmap.