Its best to avoid forking the code so you will be able to upgrade to new releases.
If you'd like to send me a signed contributor agreement and the files for the profile update handler provider I'll review it and consider integrating it. You can download the pdf of the contributor agreement on the contributor page and send the files to me at joe dot audette at g mail dotcom
Depending on what your code looks like I may implement it myself to keep it consistent with our other handler providers since it is a fairly easy thing to implement. In addition to the /Secure/UserProfile.aspx page it would probably also need to be wired into /Admin/ManageUsers.aspx since profiles can be updated from there, though we may want an event argument indicating the update was done by the admin in case that changes any decisions for the custom handler.
I'm also looking at adding a provider plugin system for user pre-delete handler so that its possible for custom code to do any cleanup of custom data if a user is deleted.