When I made the first leap from dual-booting Mint / Windows this is what I did. As someone else said, there does remain some "artifacts" after unless you know what partitions to remove, for me it was a fucky bootloader/GRUB that still retains the Windows EUFI and BIOS menus, etc. But it works.
A few months ago after more than a year of working fine, after an update (I assume kernel, as I really don't use that PC in a way to have fucked it up like that) something tripped/screwed with SecureBoot, though it was always disabled. It would only boot if I navigated to the BIOS through those stupid menus to clear the keys and reboot.
That's what pushed me to just do a full install, and I'd wanted to try KDE anyway. Just from my personal experience, a "native" install is just so much smoother!
The Neo Store client for FDroid allows you to do this. I haven't actually used the install feature yet, but it exports a list to an .aps file and says it will load and download the list (dependent on the repos you have activated.)