If I use register_post_type() to create something new and, within that function call, specify my capabilities, it's my understanding that doing so doesn't actually connect those capabilities to any specific role. Is that understanding correct?

If so, is the best way to connect those capabilities to existing roles to use get_role() and add_cap() in succession? I suspect that creating a small data structure or array over which you iterate so that all the capabilities you add to a subscribe also get added to contributor, author, etc. seems the best way to go but I thought I'd check here since you all are awesome.

I debate just creating custom roles and adding user to them but that seems like it would create more work for someone who would use this plugin and, at least at this time, I'd rather try to keep that as simple as possible.

Thanks,
Dash