Is there any way of preventing a QC3 map originating from the DMS from downloading additional tiles?

I am trying to load OS StreetView maps on my Android phone in overlapping sections smaller than 4GB, exported from a map downloaded from the DMS to my PC. I have managed to prevent memory-map from zooming into blank areas by setting a boundary ("Boundary from route" on the PC) but this doesn't prevent unwanted tiles from downloading automatically when the map is scrolled outside the previously downloaded area, in the Android app.

This is particularly nasty when the additional tiles would take the qc3 file-size over the FAT32 4GB limit, since this crashes memory-map.

There must be a flag set in the qct or qc3 file to enable downloading from DMS since os50k 2012 DMS-format maps originating from the DVD don't download missing tiles in this way.