The X800 and X800M2 are the same as far as the chassis goes with the hidden screw design. Also similar to the old X1000ES (that had an IR input port & RS232 however).
The X700 and X700/M come apart like every other player on the market with a few screws (easy).

I know some of the Sony UHD players had no IP control for some reason (baffles everyone as to why). Can't remember which ones did & didn't.

I don't sell the Sony disc players anymore after what seems to be a complete breakdown of any logical design. No auto Dolby Vision support (you have to go in a menu and manually engage it every time you play a disc that has it - even thou every other player on the market can do that) was just an unforgivably stupid screw up. As far as I know, they still have not fixed that to this day (it was a feature not a bug).
No one buys discs players anymore anyway. It has been years since I sold a disc player of any kind. I got rid of my Oppo a long time ago and the Sony X800 just sits in my rack unused year after year :(