Is there something like a "capabilities declaration" in the works to actually solve the problem? You know, something like a "X-I-Support: images, frames, ecma6, vr, xss" header? I could even imagine an "assigned capability strings" database and x- prefixes and all, but it's probably an old fool's dream in these fast-m— thing-breaking times.
Most of the problem here is failure to adhere to standards.