This is something I very recently was wondering existed. I was thinking of creating a vector logo for a project, and was curious if vector software was capable of defining relationships like you have done here. It would allow for easily determining what ratios between elements look most visually appealing. I'll definitely take a look at this and let you know if I have any feedback.
Is there actually no other existing tools that have a similar functionality?
I have done a similar tool but based on geometric relations instead of constraints, you can see links in my profile (it's only on mac app store at the moment)
Is there actually no other existing tools that have a similar functionality?