I guess Stone and Herrmann’s synths are designed to allow gates that large. And ideally all synths should be, too, but not everyone protects their inputs that well.
Also ideally all synths should set a low threshold, a volt or two, for gates, but some insist on higher.
The Kosmo spec topic says
and I’m surprised I haven’t started an argument about that. (So I just did.) 4 V minimum is way too high.