Question about Seagate Expansion Portable

Prerequisites (assumptions):
In terms of interface, the internal structure of a Seagate Expansion Portable 4 TB is the same as the 500GB.
No modification to the manufacture of Seagate Expansion Portable in the meantime.

Then Yes, SATA III
Example:
A Seagate ST500LT012 is installed in a Seagate Expansion Portable 500GB.
Seagate ST500LT012 has a SATA 6.0Gb/s interface.
See
https://www.externe-festplatte.de/seagate...
https://www.newegg.com/Product...
https://www.youtube.com/watch

I have already bought the 4TB Expansion Drive 5 times. All of them are equipped with SATA. The disks work well as SATA in a tower PC. I can recommend them for backup but not for every day use. I built a small tower with these drives (5x4TB) for cold backup. I switch it on, make the backup and switch it off again and disconnect it from the power.

I've had my hands on two different versions of the 5TB variant so far, and they both had a standard SATA interface internally. I therefore strongly assume that this is also the case with the 4TB version.

Bei WD sind die USB Anschlüsse «eingebettet» vorhanden (embedded USB interface on their printed circuit boards, and lack of SATA interfaces)
Siehe:
Data Recovery Salon
How to connect and recover USB-only western digital drives with HD Doctor suite
https://www.datarecoverytools.co.uk/2010...
oder sonst siehe
https://www.seagate.com/services-s...

Yes they have. I use 8 of these and older HDDs as a zfs raid. As long as you don't use it excessively (like a laptop, 12h spinup/day, low-medium IO) it works great.