Yes, I think this will be my next addon- call this the first draft haha. I will need to get more familiar with the gramps db api to get it to query directly but this first draft has cleared up some things that would have gotten me stuck if I went to the full addon right away. This one doesn’t do associations right now but if I created an addon I could definitely make that an option. It’s probably actually easier to map based on associations than it is to map by event roles.
The application I used is called yED. It’s completely free and has a lot of layout and clustering options I like. I use it for DNA matches as well. There is also yED live online but it doesn’t do so hot with large files. You can actually import gedcom files into it directly as well.