George E. Cawthon wrote:

If you need to cut 1" or less off the bottom, I
wouldn't worry about the cross member because it
will wider than that.

Not by a lot. On some of the hollow core doors I've been reworking
recently the bottom frame rail is just over an inch. Apparently they
don't design the door with site modifications in mind.

If the rail is under 1/2" after cutting the door down (drill a hole to
determine it's depth), I'll knock it loose and replace it with a more
substantial piece.

R