Pack what executables exactly?
Like take a copy of Nodobe Notoshop and repack it?
If that's what you mean, uh, politely, but fuck no. Malware is enough of a problem that there's no way I'd want to start downloading crap that's been UPXed since that's going to make it impossible to determine if it's legitimate or not by (most) endpoint tools, or they'll just see UPX and go 'bad shit!' on everything.