Trouble controlling MPC plugin track volume w Beatstep Pro

I'm quite used to the Beatstep Pro and find it easier to use for live sequencing than the MPC One pads. So I'm just using the MPC for a sound engine and FX processing, minimally for track recording. I have one row of the encoder knobs set to track volumes for 8 tracks which is way easier than navigating back to the mixer screen.

Someone else came across this a few years ago, however I think I have additional detail.

viewtopic.php?f=48&t=215546&p=1861152

I have the BSP encoder knobs set to "Relative CC" mode 1. Then I set the MIDI learn to Relative CC and mapped to track volume. This works fine for audio and drum tracks but not plugins (same issue with 2 different ones).

The BSP is actually sending out pairs of messages for each click, e.g. 64/63 or 64/65 in mode 1, 0/1 or 0/127 in mode 2, and then 17/16 or 17/18 in mode 2 (varies per track).

What the MPC Plugin track volume does in response is to jump up to about +6 dB. and chatter in the direction of rotation, but settles back to that value once you stop, as though it were being set by 2 different things. There's no automation recorded in the tracks. I also tried the 2's complement mode of the MPC. Tried everything. Neither the BSP or MPC documentation offers adequate detail in terms of what is really being sent or what is expected in the case of the MPC. The fact that it only affects plugin tracks is odd as well.

One workaround, apparently, is to use Absolute mode, although I don't like that since I try to get the blend set ahead of time and this forces me to redo it.

The mixer automation is on a different MIDI channel than the plugin itself. I'm using "undefined" CC numbers in the 20-30 range. Mute toggles work from the BSP's Step buttons.

I may see if it works better to have MIDI learn assign CC to the plugin's volume.

I'm on 3.6.0 but subsequent release notes don't allude to the issue or any fix.

Anyone else figure this one out?

DL

Here's what I sent to Akai support a couple weeks ago.

I set up a new program on the MPC and add drum, audio, and plugin tracks.

https://photos.app.goo.gl/axpoj4D7ntcpk7u9A

The Beatstep Pro control knob is set to "Relative mode 1". Rotate CCW, it sends out CC value 64 followed by 63 for each click of the encoder knob. CW, it sends out 64 followed by 65.

I do MIDI learning for the drum track volume from this knob, it works. Mode is set to Relative Offset.
I do MIDI learning for the audio track volume from this knob, it works.
I do MIDI learning for the plugin track volume from this knob, it jumps up to a high level and not sure if you can see it, but it wiggles slightly when the encoder is rotated CCW. It's as though it is interpreting the CC's as absolute.

https://photos.app.goo.gl/gCQp5E9dzCoGUEA76

There are 2 other relative modes the Beatstep knobs can be set to. I've tried those and they do not work. Also tried Relative 2's complement on the MPC MIDI learn, it does not help.

Updated Mpc One to fw 3.9.0, no change.

Beatstep or no, anyone else use an external controller for mixer settings in relative mode?

Their support finally got back and confirmed it. Sounds like they consider it a bug (they offered me a freebie). No guarantee as to if/when it will be fixed, which doesn't surprise me, my company is the same way.

Cheers,

DL