I tried to make two almost identical patches. In one of them the Cutoff macro is unipolar and in the other it’s bipolar.
I set the macro value to 0 when the unipolar patch is selected (so the macro doesn’t affect sound at all), then I load the bipolar version, and now the macro shows -63, which means extreme negative amount and sound changes drastically. I set macro to 0 again, so there isn’t any effect, and switch back to the unipolar patch, and macro now shows 63 and it’s again an extreme change of the sound just by switching between two identical patches. The only difference is the cuttoff macro polarity.
I think macro value conversion doesn’t work properly when macro polarity changes. 0 unipolar should correspond to 0 bipolar. For now 0 unipolar translates to -63 bipolar and 0 bipolar to 63 unipolar.
Speaking of the case when macro value isn’t explicilty set by the user, it must behave as if it’s set to 0, but as I showed above there is an issue with 0.
Also, I suspect that this bug has the same root cause. Previewing patches with different macro polarity somehow corrupts macro behaviour.