I think you’re right saying there might be a bug as the first time I tried to do what you and Daniel advised Dorico crashed.
The second time it did that (although it’s not the first project I’m trying to use chord diagrams in and I gave up long ago because how random and tedious it is to get correct diagrams as of now).
Here’s a GIF of how easy it is to do in GP (I input my tab, press A, it suggests a chord name and if I’m happy with it I just press enter, if not I just edit it… the frame rate of the GIF is low but it’s literally a couple of seconds) :
What you mentionned about Nick’s project and the fact chord diagrams don’t exist in the library : the library should be able to use any diagram, whether pre-registered by the devs or custom made by us, which I truly hope will be possible soon…