tmux supports multiline status since 2.9
Author: BlitzKraftCreated Nov 19, 2019Updated Sep 21, 2024
Labelst:enhancementc:e:tmux
From tmux man page:
status [off | on | 2 | 3 | 4 | 5]
Show or hide the status line or specify its size. Using on gives a status line one row in height; 2, 3, 4 or 5 more rows.
I don't think powerline currently supports that.
Source: powerline/powerline