They are in my way for the remodularization I want to do to have attribute descriptors.
99% of them are not actually settable properties, they are just funny properties passed from the tag compiler into the constructor to set up stuff that can't (easily) be done at compile time. I plan to rip out all those special ones and in-line them appropriately in applyArgs. I think this just removes a lot of function calls and generality that are not really needed. If you know otherwise, let me know!
