How to manage two Kobos with different collection structure in one Calibre library

[AnotherAnders]

I maintain two Kobo's with very different organisation of collections. I manage all books with their collections on my Windows 11 laptop with Calibre (Portable 8.5), and I have two libraries, one for each Kobo. I sideload all books. Many books occur in both libraries. I could create a library with two collection columns, but then I would have to switch the collection column in the KoboTouch plugin all the time. That is something I would often forget to do with my aged brain, creating chaos, as I've noticed that Calibre updates the collection of ALL books on the Kobo and not just of the ones I add or update. Is there a better solution?