When you drop a burning mob into the powder snow, it doesn't melt or destroy the powder snow. Instead, it will extinguish the mob. This isn't in parity with Java.
Step to Reproduce
1. Place down some powder snow block
2. Build a tower.
3. Spawn a zombie/skeleton in the daytime, make sure it is burning.
4. Break the entire tower and drop them.
---> The powder snow doesn't get destroyed.