minimum screen mirroring area

I noticed that there seems to be a minimum number of mirrored pixels
below which SCRCPY won't work / won't open the mirror window.
Is it mentioned somewhere how many pixels that is,
and more importantly, can that number be reduced even further?
What I'm trying to do is only mirror the tiny little area where a “1” will appear
if my chosen IM app gets a new incoming message.

Reproduce the failure with a very small mirrored crop and document the smallest area that opens a window. Then trace the screen-mirroring and window-size handling from the relevant entry points; the issue names no files or tests, so completion would require defining and validating support for a smaller area.

Written by the indexing model from the issue text.