For remuxes, from all cheap tv boxes i have tested all of them have some issues. only shield pro 2019 give me peace of mind. The only bad thing is it can't with av1.
For privacy, you can bypass google account and debloat all google spyware, for apps aurora store and sideload are your friends.
Pi-hole is great but is for dns and is easy to avoid if client change default dns. Simplewall is better for granularity in windows.