Perhaps a few ideas, hopefully something is helpful.

1. It would be nice if you could setup an alert when your project is done building (audio or visual) so you can get back to it right away.

2. When I used to work on a similar scale project, I put in a lot of effort to improve build time (initially on Windows I worked on keeping the computer defragged, and other tricks to improve build time, eventually switching to Linux).

3. It's nice to use the time doing something that is relevant to the job, like reading more and understanding the technology stack better. Reading through tutorials on new subjects, etc.

While 30 minutes is certainly a long time, hopefully the time can be used productively, it will certainly help you more in the long run!

Good luck!