So I tried reversing it - Slick on lowdpi, list-buffers on high-dpi.
Sort of as expected, list-buffers showed up tiny.
Unexpected, it shows tiny even when Slick rejoins it on highdpi.
Repro:
First: To move a window between monitors I use Shift+Windows+Arrow
Slick on LowDPI - not maximized.
Open list-buffers on LowDPI.
Jump list-buffers to high-dpi.
Close list-buffers.
Jump Slick to high-dpi
Open list-buffers.
List-buffers open tiny (see attached).
Drag list-buffers and it pops to normal size.