I know the current multiplier is 10x. My reference is lots of people won't be anywhere close to 10x, similar to yourself. I reckon 4x is above the average based on the battles I have seen so far. This mean that people with lower multipliers are extracting less from the SPS pool, which in turn means more in the SPS pool that you at 4x can earn.

So if you compound your SPS, your multiplier will grow as well and the SPS extractors will slowly get less and less.