Finally got around to installing the GMX.
Works without touching DD47/49 or DD30.
Tested so far: Pentagon INT, floppy access, SMUC, ZXM-GS, Edge Grinder GMX & Ansi Viewer
EDIT: Across the Edge (fix0) crashed at the "Outbordering" Screen around the 3 minute mark.
EDIT2: implemented D47 fix, works fine now.