Ok, yes, I understand that anything interesting we find in the wild must have arisen by evolution, and hence that it must be evolvable. But I understood your reference to "engineering" to mean "designed by an intelligent human being". In which case, evolvability is rather irrelevant.

You apparently are anthropomorphizing Nature as an engineer. That is OK with me, but please don't imagine that we are not capable of doing some biological nanoscale engineering on our own, making no further use of evolution than to utilize the enzyme systems and ribosomes with which Nature has already presented us.