i sort of struggle to see the utility of what you’re describing from a detection perspective.
it seems to me like what you’re describing would be more likely to be used to stroke egos of folks who want to be first to observe a species in a given place.
if you’re really trying to detect a particular problematic species, i would think the most efficient way to do this would be to set up subscriptions for those taxa in your place(s) of interest. alternatively, you could set up projects or queries for those species that you could periodically check.
so then the problem becomes how to determine which species you should be watching for. that could be accomplished through a combination of just being aware of potential threats by offline means and by watching for newly identified species using one of the techniques described in this thread: How to find out-of-range observations - wiki - Tutorials - iNaturalist Community Forum.