I have and old lenovo tablet (A5500-F) with 4.4.2 Kitkat. It's not very fast, but it's been very reliable for me. My favorite android game is no longer in development, and quit working on my s7 phone when I "upgraded" to oreo. It worked poorly and crashed a lot on pie. I don't know is stock pie and oreo would run it, but the samsung version won't. It works great on the tablet. Trouble is, I need the tablet to also run another app with a minimum api of 21 (lollipop).
I need to decide between trying to install lollipop or trying to find a good tablet that falls in the "sweet spot" of lollipop, marshmallow or maybe nougat. The tablet has 1 GB ram, which I've read can be a bottleneck for lollipop. 13 GB memory, 9.4 GB free.
So I'm reaching out: not for a how-to, (Not yet, anyway.) but for opinions from people with more experience. Besides whether the upgrade is worthwile, I'd also welcome advice on finding a tablet with such an out of date OS. How to know if used is okay? How to know if a new one can be downgraded, and what pitfalls that might lead to. Thank you.