Please tie Groovy compiler version to workspace

At the moment, I have one workspace for Groovy 1.8 and one for Groovy 1.7. Unfortunately, when I switch between the two, not only do I have to wait for STS to restart with the new workspace, but I also have to change the Groovy compiler version and restart. That's 2 restarts every time I want to switch between Groovy versions.

Perhaps I should use working sets for this?

Another issue I have is that when I install updates, STS switches to Groovy 1.8 again, which isn't much good when I'm working on a Groovy 1.7/Grails 1.3 project.