This question is about the Bootstrap styles used in the web gui, not Opensense-Bootstrap.
The current bootstrap version used in opnsense is 3.4.1. Bootstrap 3 has been EOL for over five years and Bootstrap 4 has been EOL for about two years. Are there any plans to update the web interface to use Bootstrap 5?
Discussion, yes, dependable time frame, no. One of the issues is that it's new but it doesn't bring anything of value to the table (compared to the work required to carry it out).
Cheers,
Franco