Our little picco boost has had around 30 ltrs on it and all i had done was change the rod out, We run 30% and i would say by the amount of pop left in the P/L we may see another 20 ltrs before we need to give the sleeve a pinch and good to go again.

You will not gain much if any by dropping nitro %, Like stated above keeping the dirt out and well maintained will give your Picco more life....