I totally understand your frustration in dealing with this issue. But please understand currently we haven’t received any information that support Microsoft Teams mobile app for use with 'require app protection policy' access control in Conditional Access policies. Some end users have already post such request in Intune UserVoice, I think you can vote the following ticket to address this issue. Many features of our current products are designed and upgraded based on customer feedback. We strive to capture any negative reviews in order to ensure that we are continuously improving our products to meet our customers' needs. With your efforts, we are committed to improving our products. Here is the link:
By the way, if there is still no response from UserVoice, it is also recommended to create an online support ticket to address this issue more effectively. Here is the link:
https://learn.microsoft.com/en-us/intune/get-support#help-and-support-experience
If the response is helpful, please click "Accept Answer" and upvote it.