I always resisted the idea of putting projects that I can't do right now on Someday/Maybe. It seemed too much like pushing them into the far future, so I would keep them active.
You're reviewing your Someday/Maybe list every week as part of your Weekly Review, aren't you? And part of that review is to evaluate each item on your Someday/Maybe list to see if it should become active again, right? That's an integral part of the Weekly Review.
Putting something on Someday/Maybe only means "I'm not doing it this week."