I tried setting exactly as in this graphic.
Total available bandwidth was ~25 mbps download speed, 1.5 mbps upload speed.
A laptop in group “guest” did a windows 10 update which was approx 4 GB. It downloaded at around 20-24 mbps.
Meanwhile, running a speedtest with a laptop in group “staff” which was set to 70% bandwidth speedtested at 1 mbps download speed.
Is there a way to use the Group Bandwidth Reservation with speedfusion active?