The BOINC wiki page on GPU crunching hasn't been updated in five years:
https://boinc.berkeley.edu/wiki/GPU_computing#Attach_to_projects_with_GPU_applications
Are there any GPU-capable projects that are missing? I know there are several that are defunct.

The BOINC wiki page on GPU crunching hasn't been updated in five years:
https://boinc.berkeley.edu/wiki/GPU_computing#Attach_to_projects_with_GPU_applications
Are there any GPU-capable projects that are missing? I know there are several that are defunct.

Just add a project in Boinc Manager.
On the right, below the project's description, you can see what CPUs, Operating systems, or GPUs each project supports. It's displayed as a little icon.
Once you have gone through the Boinc list, for the remaining projects, you can find more projects in boinc bam stats page, on boincstats.com. Just click the left column under Status schedulers.

From there you can visit each project's website, and inside your profile page, adjust the project's preferences.
If the preferences window, if it only shows 'use CPU', then the project won't support GPUs.
If the preference window shows 'use AMD GPU' or 'Use Nvidia GPU', or 'use Intel GPU', they could support it (but no guarantee if there are tasks available for them).