The Entity Token submodule for Drupal 7 provides support for chained tokens, so they can be used with entities referenced by fields. However, Backdrop's implementation of entity_token is very simple and doesn't include that, only chained url and original tokens are included.
This whole feature has been already requested in https://github.com/backdrop/backdrop-issues/issues/1440. However, that doesn't seem a straight-foward implementation. It's relying a lot on Drupal 7 Entity functions, such as entity wrappers and other utilities Backdrop doesn't have, or use the same way.
My approach here would be to start providing something simpler and more widely used, a taxonomy term reference field chained token.
For example, we can use the parents path in an alias pattern [node:_field_taxonomy_term_:parents:join-path]. We can provide this from the Field module.
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@yorkshirepudding thank you for the additional info on improving discoverability and a handy way to keep a list of projects for reuse.
Why not add a Github star?
It is a good point @izmeez and when I was researching repo discoverability I found that GitHub search does prioritise matches with more stars. This is what I was researching for:...
Why not add a Github star?
Do you have a separate development environment and transfer database and config between sites?
Wierd happenings regarding updates...