Have you as yet determined if keyservers will accept unusually large payloads?
Not yet, i plan to do some testing with that to see what the max is.
It would be interesting to know which keyservers accept unusually large files (in the megabytes range) and which just reject those updates - I expect if enough large payloads were uploaded that someone might eventually take notice.
So far i have noticed there is no rate limiting on the sks key-servers, so i have a feeling it might be possible to upload large files.
I suppose that, given you can have limitless pgp subkeys, the size of payloads can be arbitrarily large as well.