4% is just about the normal rate for PPS+ / FPPS , the only known pool that offers less than that is F2pool which has a fee of 2.5% but the downside is that the minimum payout is 5 times higher which is 0.005BTC so you will need about 315TH to get paid daily, say you have 100TH then you will only get paid about every 3 days if you have a single S9 you will have to wait for 22days (all numbers are approximate based on current difficulty), if you want the smaller threshold then you will have to pay 4% and mine at Viabtc.