Within the Microsoft Teams admin center you can set a URL to open for call-pop, see attached.
Imagine how cool it would be to have a contact pop open in Inbox, which will show you their "Recent Threads" list or automatically take you to their most recent thread/ticket.
Halo is a PSA that is already taking advantage of this feature. Here is their documentation on that: https://halopsa.com/guides/article/?kbid=1552
All you really need is some sort of URL/search/lookup/filter scheme that can find a Contact via phone number within a specially crafted URL format. (See attached)
This would be a quick win, I think.