You can share the screen of another Mac pretty easily. But it seems like it is impossible to do the same with another account on the same Mac. However, if you use Terminal to set up an ssh tunnel, you can share the screen of a second account using an alternate port number. This allows you to stay logged in to one account, while you use another account in a screen sharing window.
The Terminal answer to "ssh -NL 5901:localhost:5900 localhost" is:
"The authenticity of host 'localhost (::1)' can't be established.
ECDSA key fingerprint is SHA256:LO93WIYmRr5QACGc3TgnHdcnKPE7ttlfSm4K9LDi0rc.
Are you sure you want to continue connecting (yes/no)?"
Is it ok to go on?
Vasco: Yes. I believe that is just looking for a certificate to verify it is you. But you don't need one as this is your machine, not some public server. You can trust yourself :)
I have long had two accounts and spent numerous hours switching back and forth. Looks looks like a great solution.
I am having trouble though... 1) In your example "macmost" I believe is your username, right? I am being asked for a password after the SSH command, and it appears to not like either password. Let's say, I have two accounts, UserA and UserB... after the SSH terminal command should I give, A or B password? (BTW, the password for A is also the root password, which is why I ask.
Dennis: I believe it wants the root password.
ARD into your "work account" and then do the following on the remote computer to open a Screen Sharing window to your "personal account" on the same remote computer.