Is it possible to select some other TTS engine than AWS Polly (e.g. Azure Neural TTS)? If not, is it possible to use some other AWS Polly voice than the ones listed in the drop-down menu?
Built-in, no. You could write your own driver, I suppose, though storing the resulting file might be difficult. You can also pre-create an audio file (obviously only practical if the text doesn't change), store it in the hub or elsewhere, and have the player play that file--something I do for "static" announcements.
If you use hubitat with node-red, you can use this.
thanks, but I'm using variables so not really an option for me