...my inquiry about missing modulation wheel support on various presets resulted in the following answer. no further comment necessary.
This is not a bug, but a (missing) feature: the modulation wheel does affect not all sounds, only most of them.
No workaround known, except fully editing the patch in the Advanced Edition view (only for owners of the full MiniMg-V, not applicable here).
Feel free to come back to me if I can be any further technical assistance.