Yes, but if you install luci-app-sqm sqm-scripts should be installed autimatically, sqm-scripts-extra is not needed at all.
But you need to configure sqm befoar you can expect any change in behavior.
Could you please post the output of the following commands (run from your router's command line):
cat /etc/config/sqm
tc -s qdisc
tc -d qdisc
SQM_VERBOSITY_MAX=8 /etc/init.d/sqm stop ; SQM_VERBOSITY_MAX=8 /etc/init.d/sqm start
Also please post a speedtest result without sqm enabled (follow the recommendations in https://forum.openwrt.org/t/sqm-qos-recommended-settings-for-the-dslreports-speedtest-bufferbloat-testing/2803 on how to do configure and post test results).