I agree. what we are doing currently is also inelegant, as it stands, but the number of urls to purge when each such class is purged is incomparable to the number that get purged if all of them are called at the same time.
Because there is no other way, the _purge_them_all function was written. We tested it too and then decided against it. We eat our own dog food, and this part of it was very tasteless!
In any case, if you can try your hand at it, why not fork the project on [github](https://github.com/rtCamp/nginx-helper/tree/1.6.5), make the changes you'd like to and send a pull request. Kindly use this tag instead of the master. It already has a merged request that needs work upon. Do let me know if you need any help with that,
In fact, currently, we are rather busy with our [BuddyPress Media plugin](http://wordpress.org/extend/plugins/buddypress-media/) and hence the next release of this plugin could be a little late, unless you are willing to contribute to it :). We are only doing bug fixes for a while.
In case you buy into my request, just add the option to disable the 'purge everything' functionality.
Regards.