Bug Gridsensor observation stack > 1 and nr of channels > 3 throws error

As stated, some logic in StackingSensor can't handle situations like the one in the header.
There's a bug report submitted to Github here: https://github.com/Unity-Technologies/ml-agents/issues/5790 - not written by me - that has received not much attention. I can confirm the bug and it's a big hurdle for me in the project I'm currently working on. Wondering if someone from the ML-Agents team could step in and provide a status report or if someone else has found a workaround? I can't fully grasp the code in Stackingsensor myself and have given up on trying to fix it.