Several suggestions about move to collection menu (M)
For now when you have Scene Collection at the beginning, digital buttons (0-9) are not corresponds with default names of collections and hotkeys to change layer in object mode. So it will be better if key 1 moves object in the Collection 1 instead master collection.
When in sub-menu, for Sub-Collections same practice. But if you don’t want to move object in sub-collection, press Enter, because you want to confirm moving object into this collection, not in sub-collection.
And about markers, that displays in what collection objects now. Orange circle indicates current collection, Orange circle inside gray indicates a collection within another one.
Also Shift to select several collections (like in 2.7x) are not working now. Is it will be fixed?