Well, thank you both. If there come no objections, I'll commit it these days into modules/metadata.
actually, while I still like the idea, does it make sense to broaden the scope of the module a bit? I had started a discussion on <IfThreaded>, which turned into more of an <IfServerIs ...> idea could ping ap_mpm_query and other things. the main objection, IIRC, was that people weren't too interested in adding more containers to core.
alternatively, mod_predefine that defines all sorts of wonderful symbols (platform, server version in different flavors, etc.) for use in IfDefine
