HA Voice PE: Continuous Conversation not working with Gemini and OpenAI

Hi everyone, I just got myself a Home Assistant Voice PE and I’m currently exploring the possibilities of using LLMs and STT/TTS models from Google, OpenAI and ElevenLabs.

Problem: Continuous Conversation only seems to work properly with ElevenLabs and Piper as TTS.
When using Gemini TTS (gemini-2.5-flash-preview-tts via Google Gemini Addon) or OpenAI TTS (OpenAI TTS 3.7 tts-1/gpt-4o-mini-tts) the microphone basically turns back on immediately while the TTS audio is still playing.

I would really prefer to use Google Gemini or OpenAI because of the significantly lower costs while still maintaining high voice quality.

What can I do to fix this? Is there a way to tweak the pipeline or prevent the microphone from triggering too early when using this two TTS services?

Any help would be greatly appreciated!

Find a custom component that implements the _process_tts_stream method for tts. Or use an external gateway. For example, this project.