Zebrazilla

3.0 Exclusions
The Limited Warranty does not apply if the Hardware:
has been modified or repaired by anyone except a Valve-designated service center and the cause of the issue for which you seek service is the modification or repair, or damage caused by either;

Quote from Valve Hardware Warranty.

In other words, simply changing SSD doesn’t void warranty, but damaging the Steam Deck in the process of doing so does.

OVPN still seems to support port forwarding, though it’s worth pointing out they were recently acquired by Pango.