Will using a voice-to-text app to create my comment get me banned? Especially if it creates a transcription mistake that might be characteristic of an LLM

I wouldn't expect voice-to-text apps to produce anything that looks "Signature LLM" since it's still your words, your grammar, etc.. The occasional transcription mistake is unlikely to be an issue either, given the prevalence of humans here who use em-dashes, speak ESL, etc..