Starting builds automatically then declared

We generate the major parts of our TeamCity build configurations via scripts that run as build configurations in TeamCity and then use Versioned Settings (Git) to synchronize the changes to TeamCity.

This works fine, but... we would like to immediately start a specific set of builds when these are first declared in TeamCity and that has given us some problems.

When our script runs and generates the needed TeamCity configuration (lots and lots of XML files) and these files are then committed (and pushed) to the Versioned Settings VCS (Git), there is a longer delay before TeamCity has noticed the change, synchronized the files to the config/projects folder, parsed the files and updated the internal database. And by then the script has normally long finished.

We have been looking/talking about a number of solutions, but none of them "feel right".

• we can wait after the script has pushed the commit to the VCS, and poll TeamCity for the change (when the needed build configuration are found in TeamCity REST), and then start a build (again via REST). But this will occupy an agent for some time and the script will take even long than today.
• we can write a new TeamCity plug-in that will monitor the creation of the new build configurations and then start a build - e.g. if a specific property is found in the build. But that is a fair bit of work for something that should be relatively simple.
• we can add a new external REST service that do the same based on the REST interface

But before we venture into any of this, we just need to know if there an authorized way to do this already :-)