Sqm with variable speed

hi everyone
I'm using wireless internet connection
(ubnt litebeam m5) working in router mode or bridge (i can set freely)
connected to tp link wr940n v6 openwrt with sqm my speed is 8-10 mbit ggc (youtube + steam + epic + ...)
and 4-6 mbit fna (facebook ...)
and pure internet 0.6-4 mbit (online gaming ...)
can i use sqm to have stable latency and what setting i must choose
(per packet overhead / cake / layer of cake / ....)
thank you all ...