[2.2.11 pre1] "Ambush" mapthing flag gets lost in Binary to UDMF conversion for custom objects

See title.

So far, I've encountered this issue with both versions of the Egg Slimer in my Retro Bosses addon. Both are supposed to speed up with each hit until their pinch phase, but this doesn't happen in the current prerelease. Using -writetextmap, I was able to see that some of their arguments are blanked out instead of being properly converted, while others have negative values, for some reason.