If TTS audio is being cut off at the beginning, this is because the player needs some time to switch to playing out the stream. The only good solution for this is to add a configurable amount of silence at the beginning of the audio stream, I’ve modified Google Translate and VoiceRSS to do this, they can be installed manually as custom components.
Custom integrations that override core integrations are not accepted in HACS, but can can still be installed through it as custom repository.