I would like to second that request for selective restarting. With a number of persistent external applications like Rails in a shared hosting environment, it's an unnecessary burst of CPU to reload all of the applications each time one of them needs to be uploaded. This is particularly annoying with a capistrano deployment for Rails. It's the primary reason I suggest to customers the use of Mongrel instead of LSAPI.
For the Ruby LSAPI, couldn't you just make a lswsctrl sighup <extapp_name>? That would be very useful. And just being able to do it through the web admin interface would be a great start.
By the way, LSWS + LSAPI is pretty amazing irrespective of this fault. Please keep up the good work.