IDK if you consider yourself tech savvy or not, and IDK how much effort you're willing to put in but you could try Tasker. I'm sure whatever these apps do, still not sure why anyone would need an app that scrolls for them, but they have to work on some type of logical execution, I'm assuming scroll every few seconds or something, but with the right extensions Tasker can probably do this. It would require some effort to program the profile but you may also find it more flexible than someone else's idea of how it should work. Tasker can also help with your session limit thing, with its ability to open and close apps based on timers, time of day, location and more. Perhaps if you were into something productive like coding you would feel less addicted to your device since it wouldn't be pointless surfing. No offense, you may not consider it pointless surfing but that's what comes to mind when people talk about limiting screen time. Anyway, Tasker becomes a skill with a little effort.
Good luck.