Weird behavior with dwm

[ghost]

dwm-6.2

trayer-srg-1.1.8

trayer launched from ~/.xinitrc before dwm like this:

trayer \
    --edge top \
    --align right \
    --width 80 \
    --widthtype pixel \
    --height 16 \
    --heighttype pixel \
    --expand false \
    --monitor primary&

This is what happens at startup:

This is what happens after I start an app that has a systray icon:

This is what happens after I close that app and systray becomes empty again:

Is there a way to tell trayer-srg launch in the right position from the start? Perhaps some dwm rule for trayer window is needed? I wouldn't like to resort to fooling dwm with ugly hacks like launching a void systray app at startup and quickly close it just for the sake of enforcing trayer's correct position at the edge of the screen, on top of status bar, not under it.