That is my understanding. You get more SP over time to offset inflation, but that inflation also drives the price down (more supply = lower prices). Without new demand, I'd expect these to offset each other for the most part.
That means the only way to gain here is to curate or post (grow your SP above the inflation rate) or hope demand increases and drives the price of SP up so the SP you have gains in value.
inflation ...(more supply = lower prices) . not really ever, but especially in this case not really.
Because even if what you think you know about money supply and inflation was true (spoiler alert. its not), its only true all other things being equal.
Trying to explain a shift in price based on a delta in the money supply in this situation is like trying to use the Coriolis effect to explain why your toilet flushes a certain way. There are simply more proximate forcces driving the price.