Is your feature request related to a problem? Please describe.
No.

Describe the solution you'd like
To my knowledge, MARS5 and the upcoming MARS6 are the sota English TTS models with open weights available - https://github.com/Camb-ai/MARS5-TTS
Given that AllTalk TTS already supports multiple models, I'd like to know whether the maintainer would be interested in adding support for MARS in v2.

Describe alternatives you've considered
Do nothing :/