“Expensive”, how? It’s not a product that is for sale.
MegaAGS takes care of all of that for you, and 5× scale doesn’t make much sense in any other resolution than 1080p — I don’t think any of the other cores on the MiSTer support the 5× scale/crop in any other resolution either? In any case, this is pretty trivial to set up even if you’re not using MegaAGS, so other setups are free to use it — there’s nothing MegaAGS-specific about it.since it doesn't work for users without a 1080p monitor and many users haven' set up a shared storage space (that MegaAGS Workbench can access in the MiSTer filesystem).
Amiga has such wildly varying offsets that you really need hand-tuned settings per-game. It’s not like e.g. SNES where a couple of pixels nudging the image up or down will do it, its range is 0-60 pixels, depending. We didn’t implement it like this just to be non-standard