Well I have said something (but crucially, not exactly) like that before. The problem with @Giltil’s statement there is that it seems to describe a universal generalization. I would not say that "many possible but unrealized biochemical solutions exist to [all] complex biochemical challenges." I think his statement implied the [all] that I inserted there.
I would say that we know of enough examples of it being true that many possible but unrealized biochemical solutions exist to a large diversity of complex biochemical challenges, that we have no good reason to think the types of “waiting time” problems ID/creationists concoct retrospectively for adaptations in existing lifeforms, are founded on anything real. They are just extrapolating from a handful of cases of adaptations known to be relatively constrained, to basically most of the genetic differences between species. A particularly egregious (and utterly ridiculous) example is the Sanford et al. 2015 paper that was brought up in this thread by Gilbert.