"Workstation" is a real stretch.

• The hardware in those things is underpowered to say the least.
• The way X11 is implemented there is no acceleration so that's going to suck to use.
• The connectivity is atrocious. Maybe WiFi and Bluetooth if the package removals doesn't wreck things and even then no guarantee you'll be able to pair anything, and maybe one usable USB-A 2.0 port.

A fun project for sure, I'd have a blast doing something like this. But the expectation you'd have something actually useful afterward is not realistic. If you want a workstation you're far better served by bolting a NUC-style computer to the back if the TV and using that.