Just received my speed controls (3X TMM 16018-3 Car / Boat EXPERT+) back from MGM after having the firmware upgraded to the Ver. 3.21 . The turn around time in total from the time I sent it to the time I got it back was 1 month (Australia), not the quickest but there was no charge from MGM for the upgrade, CC_03 cable or the return postage (I did pay the postage to send the 3 controls $60Aus. 3-5 days delivery).
I can confirm that the newest firmware will operate with Futaba Radios in "HRS" mode (I use a 3PKS with th Futaba Fasst 2.4GHz system) this is a welcome update as I always use digital servos and they will now be operating to their maximum performance.
I have yet to test the LVC as my system would go to reduce RPM once the edge came off my packs @ about the 2mins mark, I will post my findings after I test drive my car.

Cheers Andrew