Can you or can you not sign a message from an old address?
No, I cannot as I mostly convert the crypto to fiat and used different address. Still I can sign one from the recent one from which I signed a message already.
1JywwXphRygZ42KPvP7qtQYccXM2L8hpTu
No
Right, so you can't sign from any old address and there are no other ways of confirming that the same user is still in control of the account? Very convenient.
There are many people here who have posting gaps that does not mean they should get a red trust on the basis.
Actually it can depending on what they try to do afterwards.