The major problem with SCE: Its entire functionality is based on a custom implementation of the comment form. It does not reuse the standard comment form of WP core.

This means that any potential additions to the regular comment form are inherently lost, and data as well as interactions of other plugins is not accounted for. The Simple Comment Editing plugin forcefully bypasses all of that by introducing custom data structures, custom logic, custom hooks, and a custom presentation.

The consequence is that other plugins, like the recently covered Mollom plugin, are not able to operate as intended, since the underlying operation on the comment entity is hidden away from all other plugins.

That is, of course, unless you expect that thousands of plugins in the same space would magically contain integration code for all other plugins... which is utopian.

The general idea of making plugins reuse and leverage "core" functionality (as in WP core) does not seem to be widely accepted and adopted among WordPress plugin developers yet — 999 of 1,000 plugins are scratching their own itch; dismissing the fact that 999 other plugins won't be able to integrate with your plugin.

That said, the APIs provided by WP core, as well as their technical maturity, certainly take a good amount of blame for that. For other applications (e.g., Drupal), the aspect of API maturity and re-usability plays a key role; in particular for their ecosystem of extensions — the API design allows all extensions to seamlessly integrate with each other; there's no need to scratch your own itch, unless you're waiting for a new API feature that will be included in the next major version only. I'm personally surprised that WP reached this level of adoption and popularity, given the APIs that it provides.

But anyway, aside from that shortcoming and architectural problem, the plugin's code actually looks relatively good (especially when comparing it to many other plugins).

As one of the co-maintainers of the Mollom plugin, I'd love to support this feature, but I hope you can understand that it is not within the realm of possibilities to add custom support/integration code for each of the gazillion plugins that are operating in the comment form context. Instead, I'd like to gently ask the developer of SCE to change the plugin code to reuse the standard comment form functions of WP core — in fact, you might be able to find some nice inspirations in the code of the Mollom plugin :)

Speaking of, which plugin provides the "Preview" button here on WPTavern? Yet another plugin I'd love to support, but alas, only possible if it doesn't scratch its own itch (again).