I have OnePlus 7 Pro that I successfully flashed with LineageOS 21 with MicroG. Do you have some interesting apps or ideas to take advantage of it? I thought of some Magisk modules. Maybe someone is more experience than me! This is the spare smartphone, the main one is GrapheneOS, so I don’t mind breaking stuff.
I think it may be based on ksu, but also uses superkeys with passwords or something. I don’t know much about its security, you may want to check the issues tab on github or generally the project itself.
From the security standpoint, I think rooting is always against the security. That’s why DivestOS and GrapheneOS are against it, and it shouldn’t be tried. However, I was interested in Shizuku that also is some another hole to patch up when exploited.