Unity Upgrade: Project/Library folder reimport, Can we set it reimport as Android/iOS instead of Standalone Platform?

We have a huge project of nearly 20GB of Textures. When there is an upgrade of Unity version / cleanup of Library Folder, it will trigger a project reimport. The default platform seems to be PC / Standalone. However, if our initial target platform we want to be is Android/iOS , we have to wait for it to complete reimport and PC first, then click change platform, to reimport again as Android/iOS.

my question would be, can we directly set Unity to import as the platform we want from a clean state? (e.g. Unity version update/ after Library folder cleanup.). That could probably saves of hours of wait time.