Use descriptors for Extensions?

I'm writing up an extension, and my wrists hurt from all the typing :) I wonder if we could use descriptors to cut down on the boilerplate. For a typical property that comes from the properties dict, it'd be something like

class MyExtension:
    description = Property()

where Property is a descriptor like

# untested
class Property:
    def __set_name__(self, owner, name):
        self.name= name

    def __get__(self, obj, objtype=None):
        return getattr(obj, "properties")[self.name)
    def __set__(self, obj, value):
        getattr(obj, "properties")[self.name] = value

I haven't really looked to see if this works for many of the extensions. Some downsides:

1. Unclear how this would interact with static typing. But properties are supported by mypy, and descriptors are prosperities, so it might be doable.
2. Makes . lookup a bit slower, though on par with @property so maybe it's acceptable.

Start by reviewing the extension classes that expose values through their properties dictionaries and compare how much boilerplate they currently require. Determine whether a descriptor approach can work across the extensions while preserving static typing and acceptable attribute-lookup performance; the work is done only after those trade-offs and scope are established.