I think there is currently no way of doing this in a really good way
find().count() > 0 would be the best direction
but then you need to do the find already inside the content collection(s) otherwise you will look at subpages as well
got this tip from Aske a longer time ago, don’t know if it still works: @if.hasNodeType = ${q(node).find(’[instanceof Vendor.SiteName:NodeType]’).is()}