You can redefine “design” to mean “seven buckets of fish”. Just remember that an intelligent design goon can say, with perfect sincerity, that ‘a tree grows flowers to attract pollinators’, and leave out the caveat, and sound just as credible as you do. Or, more accurately, you can say ‘a tree grows flowers to attract pollinators’, and be misunderstood, because of that small word ‘to’, leaving the impression that trees have made a good biological choice in growing flowers.
That is how you leave people thinking teleologically, and specialist vocabularies be damned on that account, in whatever field. I prefer that such terminology not be used by anyone, precisely because it permits poor thinking, and has a tendency to spread into other areas as norms masquerading as objective, scientific statements of fact. It is how Darwinism becomes perverted into social Darwinism.
If the function of the function in this functionalism is to provide an intention for a design you are using the same form of reasoning as ID does - the functionalism becomes just a camouflaged version of ID, with an even weirder teleology arising in the function itself. It makes teleological thinking more persistent than it already is.
Anyway, I don’t think this is getting anywhere.