While I'm certainly fully OK with only attaching ZIPs in the
end (does size really matter?

), you nevertheless made me curious
why .7z files could be a security threat. This is off-topic of
course, but also I'm usually trying to avoid executing
self-extracting EXEs just because I see a 7z icon. It's simply
too easy for a wolf-in-sheep's-clothing-attack.. you never know.