http://bugs.winehq.org/show_bug.cgi?id=36025
--- Comment #1 from Ken Thomases ken@codeweavers.com --- I'm not sure that working around the size limit is what we want folks to do. If we were willing to accept larger attachments when split into pieces, we'd just accept them as whole files.
Mind you, I don't know if the current limit was something that anybody associated with Wine picked or if it's just a Bugzilla default that we've not bothered to examine.