but since you just did that about a month or two ago, that'd be a waste.
Not really a waste. It doesn't matter if you reapplied new paste yesterday, you always need to thoroughly clean and reapply after you take off the HSF for any reason.
The reason is microscopic air bubbles that are created when you reseat without reapplying. We see enough people around here that try to reuse even one day old paste that have TERRIBLE temps afterwards.