Pinetab2 as a tablet, or some x86_64 tablet of which there are many.

For TV, use it as a dumb display for some FOSS TV box, running something like libreelec.

As for DRM attestation, that's not the responsibility of anyone but the DRM vendor, so ask them.

If you use services requiring DRM, you are one of the bad actors, why should we care about what you think ?