It means I need to get a real life!
I am still very conflicted about making internal datums to features. On the one hand, I like a clean feature tree and on the other, I don't like having these things locked up by one feature.
As for your direct question, I might try to use an earlier feature to establish the axis for a datum plane to assigned to. Any extrude with a geometry point will generate an axis for me. I can also place geometry points in sketches for a datum reference at a later time. I guess it all depends on just how many superfluous planes or axes I need to create to get the end result. Whatever I choose to do, I usually regret it later anyway. So for me, a skeleton type sketch(es) to maintain my intent is the easiest way to manage highly dependent models that are in flux as the design evolves. If I hadn't committed to drawings yet, I will usually allow time to clean up the models for better sustainability.