I've had a thought in the back of my mind to write a replacement/alternative for the GTK file picker for years. I've probably spent at least a day total using i

I've had a thought in the back of my mind to write a replacement/alternative for the GTK file picker for years. I've probably spent at least a day total using it throughout my life, so it would make sense to spend a few days on it to help myself and others. To improve it I would remove several features I don't need, add features I would use, and repair subtle but important workflow issues such as key commands and widget focus issues. But how extensible is it? Would it require a recompile of GTK? Or perhaps a shared library plugin? Realistically, the likelihood of me actually diving into this is low due to life keeping me too busy.