Thanks! Yes, more features will be added, my development tracker is over here but development might be slow over this week because of work.
I'm not so sure about adding a key for deleting faces. My general philosophy with developing Sprytile is to lean on Blender's workflow rather than coming up with new ones. For mass face deletion, I like using the paint selection tool to select the faces and deleting as usual but if there is demand for this, I might consider implementing it.
I haven't posted this to forums yet, I still need to do more promotion of the tool. Thanks for the idea of posting there!