Select has an Auto-Archiving feature that will automatically archive projects you haven't interacted with for 40 days so your home screen remains clutter free with only your most recent projects!
If you want to go back and view any of your old projects, you can easily get to them by just clicking the Archived tab on your home screen:
If you're missing any projects, unarchiving will have the same affect as importing a new project. When you unarchive, it will run the background processes again to make sure your AI assistance is up to date. You can find the unarchived project on your home screen again after unarchiving, but do note that it will sort into your list of projects based on the original date of import (so it might have slotted in further down your project list if you're looking for it).