That’s correct for the most part. The stereo mode will essentially duplicate the instance to be able to process two different signals at the same time. Once it’s engaged, the panning will be controlled by the source tracks. Allowing the plugin to override the original panning configuration of the source signals (assuming it’s even possible) would defeat the intended purpose of the feature.
As you point out, you can’t assign different cabs for each channel while in stereo mode, but there’s no reason to include that feature when the mono mode already works better for that purpose. For example, most DAWs (if not all of them) will assign one instance per thread. If you engage the stereo mode, the DAW will duplicate the CPU usage on just one thread. Instead, if you’re using two separate mono instances to process two different signals, the DAW will assign them to two different threads, resulting in better overall performance. Otherwise, if you want to do something similar with mono sources (stereo output on single guitars) you can already do it with a mono instance since the output doesn’t depend on the mode switch.
Anyhow, thank you for taking the time to stop by and let us know your ideas, we really appreciate your feedback. If this topic/suggestion becomes something common in the future we may have to reconsider it. Also, drop one of your mixes once you’re done on this thread to check it out.
Thanks again!