You ought to give Effie a try… still a new app, so in its early stages, but mindmapping is very nicely integrated into it. And the developers are very amiable. And it costs a small fraction of Tinderbox (in fact, it doesn’t cost anything at all at the moment). Also, it’s cross-platform (Windows, macOS, iOS).

https://www.effie.pro

Amontillado wrote:

Well, I was weak. Paid my upgrade fee, back to Tinderbox.

I remain very addicted to Devonthink. What I'm hoping to do with
Tinderbox, mostly, is use it as a corkboard or mindmap.

If Devonthink had those view modes it would be amazing.