Floor_LowerToHighest(tag, speed, adjust, force_adjust)
Lowers tagged sectors' floors to their highest neighbours, optionally applying a lip. If their neighbours are higher than their current floors, motion will be instant.
A speed of 8 is equivalent to most of Doom's specials. 32 is equivalent to a few others and is the same speed as that of conventional Doom elevators. Dividing speed by 8 results the number of units of movement per game tic.
Adjust sets up the lip. To get the lip size, subtract 128 from it, so a lip of 8 units needs adjust set to 136.
Force_adjust if set to 1, it will cause the lip to appear even if the current sector position is the same as its lowest neighbouring floor. Needed to emulate this special depending on conventional game behaviour (Doom vs Heretic). Typical to Doom is 0 and for Heretic it's 1.
The reason adjust is set this way is because this special was imported from ZDoom, when UDMF didn't exist, and was limited by the Hexen format.