Same above, but with the Emerald Mine engine in RnD:
And here's how fast it falls in Rocks'n'Diamonds' own engine:
RnD seems to be the clear outlier here. In other engines, elements pass through magic walls as fast as a player passes through a door, but in RnD, they pass through magic walls just slightly faster than a rock passing through quicksand.
Is this the speed at which elements fell through magic walls in the original Boulder Dash? If it's expected for BD magic walls but not other magic walls, I'd suggest adding a "slow EM/DC magic walls" compatibility setting after fixing it. If it's inaccurate behavior for all magic walls, I'd suggest adding a compatibility setting for slow magic walls in general after fixing it.