At least from my research, Kinoite is Wayland. I think you can go to KDE (Plasma) settings, find the “About this System” page and it should say “Graphics Platform: Wayland”. GNOME and KDE are desktop environments, X11 and Wayland are display managers (I think of them like rendering engines).Though it’s true that Spectacle has issues on Wayland, apparently all screenshot apps do, due to security restrictions and slow development. But Spectacle works great on KDE because Spectacle is made by KDE, and gets special privileges when run on KDE desktop. Same with GNOME screenshot when run on GNOME desktop. Third-party screenshot tools don’t get these privileges and don’t work well on either (at least when using Wayland), you can read more about it here: https://github.com/ksnip/ksnip/issues/727.
As far as Textractor goes, I haven’t had any issues with text hooking, but from my experience it heavily depends on the game, and I’ve only tested 2 games on linux so far. But if I’m reading you correctly…are you using Firefox inside WINE?
By the way, in case you are interested, I do have a hacky script that lets me use keyboard shortcuts to attach screenshots and audio recordings to my anki cards. Just be warned that it is QUITE hacky, especially since I use a Fedora Atomic distro.