Shouldn't overlapped and regular terminal be the same?

[singalen]

Looks like Cmd-Opt-O terminal shell is different from bottom of the screen terminal shell: I can see a command scrollback in a bottom terminal, but not in Cmd-Opt-O terminal.
I expect them to be the same.

[singalen]

I don't really see a reason to have two terminal sessions at the same time while only one or none would be used.