32MeTpa
Auto-translated
UPD. I've basically figured it out. I copied one of the developer maps for videos with an underground area and edited it to suit my needs. At the same time, I checked the settings of this map and found no differences from my own, yet it opens with the underground area, while mine doesn't... well, never mind.
0 - the map will open on the surface
1 - in the underground.
Most likely, this also works for videos.