Why don't I see 4.6 Mbps up when I change the downlink value to 25%?
When changing the downlink values you should keep in mind the overhead involved in AP to multiple SM communication. As you change the downlink value to lesser than 75% you then introduce more overhead. By putting the downlink value to 25% doesnt mean you should see a great increase in upload traffic. Example would be 75% downlink and 25% up = 4.6 Mbps down and 1.6 Mbps up. Change the downlink to 25% and 75% up = 2 Mbps down and 2.3 Mbps up. You will not see 4.6 Mbps up when dedicating 75% to the uplink. This is because the higher amount of overhead introduced is using more bandwidth.