Xbox Series S/X internal SSD manual upgrades (plus bigger more affordable expansion cards?)

Are you using a Series S/X?

Series S/X optimized games can only run from the internal SSD or an expansion card made specifically for the Series S/X.

Xbox Series X|S games can not be run from USB storage devices. These drives are too slow for Series X|S games, regardless of them being on Game Pass or not.

Series X|S games can only be played on either the Internal SSD, a Seagate Storage Expansion Card for Xbox Series X|S or the WD_BLACK C50 Expansion Card for Xbox

If he has a Series S/X and is trying to play a Series S/X optimized game, it will only run on the internal drive or on an expansion card made for the Series S/X. It won't run on a regular external hard drive or SSD.

Not really...

Xbox Series X games / upgrades / updates has to be installed onto the Series X internal or expansion card SSD,

You can have Xbox One games on your external hard drive that will get an Series X upgrade but the games will need to be transferred to the Series X and then the Series X upgrade will need to be downloaded onto the Series X SSD,

As an example...

I have Marvel Avengers on my external hard drive that will get the Series X upgrade and I will transfer the game over to the Series X SSD ready to download and update the game to the Series X version when available.

You can use a hard drive that is USB 3.0 or 3.1 It doesn't have to be an SSD. I have a regular HDD myself and it works fine.

On the Series S/X, Series S/X games and upgraded One games will only run from the internal drive or the Seagate Expansion Card. You can still store the games on a USB storage device and move it to the internal to play if needed.