I typically use "Create Base Feature" like a little direct modeling enclave - a safe place to take advantage of non-dependancy-based modeling techniques within my otherwise parametric file.
I would like to have a similar feature for parametric modeling. A feature in my timeline that contains a fully parametric model. I currently do this with xrefs, but I could imagine a solution where you could edit a parametric model within the context of an otherwise non-parametric one.