Radikill, I understand your request. However, the answer is no.
The potential for abuse, even with your proposed list, is way to high.
In effect, using a normal 'ban' is the 'only on one server' way. Management of allowing unbans on some servers but not on others using UBan would then become nightmare.
I'm not sure if you've seen the Facepunch forums "UBan" release, but too many people whined when they thought it was a program that would ban from ALL servers.
We repeatedly had to tell people, "NO, this is only for those servers who make a private database"
Your best bet would be to find/make a few good friends who host thier own servers, and make a database of your own.
I believe at one time we were part of about a 8 server shared list.
This is no longer the case, as the majority of the servers are now out of service or formed thier own new communities.