Using pre defined variables in richtext

A customer came up with the follwoing question:

Can I use variables like ${{first_name}} (first name of the webuser) in a richtext field?

His use case? He wants to write a personalized page including the name of the logged in user. It’s possible to do conditional content on login, but using specific variables is only possible if I code him a widget. Is there a way to define “global” variables like ${{user:first_name}} or {{site:weburl}} that can be rendered in a richtext field?

Of course offers some new problems like caching and additional rendering. But still a good idea.

There isn’t currently, no. Worth exploring how systematising that might look.