

As others say, it can be done. If you want more normal umpf, you’ll need to mount parts of the filesystem to your ssd. You can mount /home or / on ssd, or have an overlay file system as a file on an ssd/hdd, or use bcachefs with back propagation to the usb, or similar fancy setups.
So you’ll boot linux kernel from the usb, but most disk activity will be on your ssd. Fun project, but not super easy/practical if it isn’t done automatically.
My old HP microserver is ‘made’ to boot from a usb-stick inserted on the mb.
Anyway, perhaps an AI can suggest a script to do what you want ?
‘Competition’ is perpetual economic war. People and environment dies/suffers and value are stolen by corps/oligarchs… You have been propagandized…