@kpgraham that could make Stop Spammers useful in more situations. The current version doesn’t prevent contact-form submissions with static caching schemes where cached HTML pages are served directly from disk files, but could work fine if IP deny code was automatically saved to .htaccess. Forgiveness might require manual editing, depending on the functionality provided, but I suspect most website owners are far more interested in blocking troublemakers than in having an easy way to forgive them. As to blocking false-positives, there is no reason .htaccess blocking would have to be more permanent than the current method. Stop Spammers could periodically purge IP deny statements older than some user-specified age.
Incidentally, even though this issue currently prevents use at most of my sites, the functionality of Stop Spammers is otherwise terrific!