Reproduction

Despite being the fingerprints of the Mycos, the fungus is still alive, and reproduces as fungus does.

Sporebound are constantly breathing out spores. The Mycos decide who they want as hosts, the Sporebound don't get a choice. Some sporebound avoid their loved ones. They might even end up colonizing someone they don't like. And now have to teach, and deal with all the time.

The host always gets a choice, an informed choice. They see the Mycos in their dreams and choose.

Sporebound can try to force the issue by breathing hard directly into a person's mouth. They can try to convince the Mycos to symbiote with them. The person still gets a choice. If they're dying, they need at least enough brain activity to make that choice, and the Mycos can bring them back