Than I suggest you are using a tablet as a PC or at least with a PC mentality, and as such may have issues with the lack of a centralized file system.
There is nothing "wrong" with your approach at all.
iOS and Android photo apps are all built similarly. They have their own way to manage files and edits. Expecting them all to play along nicely will be a challenge for you.
I assure you, if you accept that all iOS apps will drop the files somewhere in your Photos App, and that the Photos App can be synced with your Mac, but not with iCloud Drive, you'll be fine.
I use a Mac and Lightroom and many apps on my iPad. I simply let the system do as it is designed to do. Once I have edits or files to play with in Lightroom, I add them (on my iPad) to a Shared Album I call EDITS from IPAD, let it sync to my Mac, and grab them from the OSX Photos app for export to a known folder in full size and then in to Lightroom.