Hi Alice,
The focus of this challenge is the profile, not the activity around it. Once a profile is improved, it should simply stand as a better profile. Adding a marker does not add context about the person and does not make the genealogy stronger.
This is not about showing that the Texas Project, or any individual, worked on a profile. That value lives in the work itself. The tree is where we visualize the collective effort. The profiles are where the work lives.
Regarding starting sooner; Fair point, though full disclosure, the idea only popped into my head and came together yesterday