Hi Paul,
I'm using a Roland RD-2000 as my sequencer, connected via USB to my M1 Max Mac Studio. I'm using the most up-to-date driver for my RD-2000 with my Mac. Changing the "sample buffer" within the driver software does not seem to affect any of the issues I address within this post.
I'm recording MIDI using Garageband, and I'm running Vienna Imperial Bosendorfer as a VST plugin within Garageband.
Here is a MIDI file I saved from Garageband in which I used full polyphony and full samples for the Bosendorfer. You'll notice from the beginning that there is muting of notes. After a few minutes, the plugin itself stopped working entirely even though the MIDI notes continued to be recorded - https://drive.google.com/open?id=1GA11Q77f8Hei324_s9Sy1sEC_OlCBLEO&authuser=sshimel123%40gmail.com&usp=drive_fs
Then, I restarted Garageband, re-launched the Bosendorfer plugin, set polyphony to 160 and samples to omit soft pedaling, and recorded. This time, I experienced no muting or any other issues - https://drive.google.com/open?id=1GAVYrs_WsbdvtwA4jdwbqiPfl4BqTxth&authuser=sshimel123%40gmail.com&usp=drive_fs
I can confirm that when using either the Imperial Player or Vienna Ensemble 7 that the issues I experienced in the first take with full polyphony occur in the same manner. Vienna Imperial Player often crashes when using full polyphony. I'm not sure how to send you those error logs, but I can if you'd like to see them.
Thank you for your help. Let me know if I can send anything else along.