Microsoft Planner @Mention and Comment Notification in Microsoft Teams - NEW VERSION

First,

Thank you, Thank you, Thank you!!!

This is amazing and saved me so much troubleshooting!

A few questions/problems.

1. I still receive the error message for the link directly to the planner on the web. The Reply in Teams Planner works great. Perhaps this is because I don't have admin access for the Tenant?

   {    "error": {        "code": "NotFound",        "message": "TenantId not found",        "target": null    }}

2. In the Trim step I sometimes get an error about negative integers in the old and new version.

   trim(substring(body('Html_to_text'),0,lastIndexOf(body('Html_to_text'),'@')))

   trim(split(substring(string(body('Get_a_thread_post')['body']), add(indexOf(string(body('Get_a_thread_post')['body']), '@'), 1), indexOf(substring(string(body('Get_a_thread_post')['body']), add(indexOf(string(body('Get_a_thread_post')['body']), '@'), 1)), ' ')), ' ')[0])

3. Is it possible to tag multiple people in a comment?
4. Is it possible to make the Teams Chat message originate from the person making the comment? Or perhaps the Group? Right now they all come from my account which can be confusing.