I've come across an issue where I don't want to import or have anyone else use the import feature of Usync in Umbraco 10 as it's possible between repository versions and database is causing some odd behaviour ( might be due to different developers attempting changes and then importing the incorrect data types or doc types). For this reason, could I delete all the contents under /Usync/v9 so it's a clean slate. Once the changes are correct then introduce Usync again? Or is there another way I can ignore whatever data types etc are currently in this folder? Finally, I'll want to turn this back on. This is temporarily to stop anyone importing old data types so going forward I would like to continue using Usync once it has the most recent changes.

you can handle what is exported / imported an how using settings. https://docs.jumoo.co.uk/usync/uSync/reference/config

So I assume I could still delete the folder (just in case there are other issues which may not be known just yet for other parts)?

yes. i mean, if you want to do all the corrections in your dev env. You can delete all the files and do a new export. But i don't think you need it. I think a full export will do that for you. Will override everything in your disk from what is in your database.