As I said, I never saw the FW16 except in pictures and everything I know about it was from the net. I might be wrong about some of the things I wrote.

So, does it really have a headphones jack or not?

My X60T headphones jack only recently started to cause troubles after many many years of use, but it was an easy fix: drill 3 tiny holes in the connector casing and push a needle through each one to bend the contacts tighter.

The F13 has it, the FW16 does not.

Anyway, I'd rather just disassemble the expansion card and solder in a new port should this ever come to pass, as it's just a question of undoing two screws:

https://community.frame.work/t/whats-inside-the-audio-expans...

I don't know about the 16, but my 13 definitely does have one.