Sorry, but APRSISCE/32 currently only supports either Internet-accessed or locally cached 256x256 PNG tile sets that are OSM-compatible. There IS an easier/better way to prefetch tiles for a given drive path, but I need to get it documented. If you want to experiment, try the following sequence:
1) Create an object at one end of a driving path
2) Move that object through points along your "drive" (Don't make too many points)
3) Convert the object to a MultiLine object
4) Zoom to a desired level and "Drive" the object
Of course, you will want to have Internet Access available when you do this and as with all prefetch environments, you'll want the purger turned off.