[jimis]

Who are the phone/tablet manufacturers that are friendliest to rooting or installing open-source Android clones? It's a pain to do that on my Samsung Galaxy devices...

I'm looking to buy a (new) 10'' tablet for that purpose.

[madboston]

Google Pixel is one of the easiest. Usually carries a lot of dev support even after Google themselves EOLs it.

[fsflover]

Not Android, but have a look at Librem 11 tablet.

[izacus]

Google (Pixel Tablet in your case).