Is a written i.e. text or e mail, thank you note a good idea after an interview?

You can do both. Send a written thank you note with one sentence to summarize a highlight of the interview right away. They'll receive it in a day or two. Then you can follow up with an email where you can ad anything that you may have forgotten about during the interview and really want them to know about it.

IDK. Maybe if that is the way they contacted you in the first place. I so think and e-mail would be more professional though.