[feature] Completing stages and access to prior though uncompleted modules

I decided to practice lower priority content for one of the math stages, and assumed that I would be able to go back and have access to the other practice modules that I had essentially skipped over. Not sure if this is secondary to the stage being the one prior to the practice test, but I can only review the practice modules that I had already done and cannot take any more practice modules, including those that I skipped and had hoped to go back to. I think it would be more useful to not close out access to the practice modules within a stage just because a certain number of modules have been completed, especially since my practice test "date" technically isn't set for another several days, and now I cannot seem to have access to the smaller practice modules.