This is not really in our scope, but we see and understand the need, and it's very sad to hear that TB-Rescue has closed (seems to be closed now).
We will definitely keep this under consideration, and I have this topic bookmarked as a reminder to myself.
The case you present sounds fairly easy to implement actually, at least in my initial thoughts. I also notice that they had a site call TB-Run. Since we don't have experience with any of the sites, it would be interesting to hear what they did more, including TB-Run. We have of course known about the sites, but we don't do much trackables.
There are some technical details I would like to look into. Like if we can use the Geocaching Live API to know who owns a trackable. To me, it sounds reasonable that only the owner of a trackable can start a rescue mission for example.