I use them like that as well, including a list for 90fps upgraded ones that I already downloaded but need to grab the 90fps version off at a later point etc. Although it's true the lists are getting a bit large, not enough time to really get through it all of the 'watch later' and 'to-download' scenes at the moment lol.
I also use a wishlist of paid-videos I'd like to get at some point, although I read PPV stuff is going away? That would be unfortunate if true, like I probably wouldn't subscribe to a site like StripzVR because their sub is silly expensive but I do like some of the models and get some of their scenes as ppv here. Hope that stays possible even if it's less visible.