To be honest, I do not know which side the problem is on, yours or ToneBoosters.
VoicePitcher 4 has a big latency in Cubasis 3.4.3, which is not compensated, including when the track is frozen. Although the “Mix” parameter in the plugin is not set to 100%. I have to manually move the track on the timeline. I assume you can negotiate with ToneBoosters to compensate for the latency.
I have already written to them, but they have not answered me.
I am using iPad Pro 12.9 2020, iPad OS 15.6.