v2023030a, a good number of improvements:

* move tc commands to functions as they're the same for ingress
  and egress.
* now allows starting from hotplug *if there is no qdisc already active
  on nssifb*
* reverted shaper burst value to standard SQM - seems to perform better
* calculated queue limits if no queue limit is specified by the user
* allow setting flows via the advanced options string
* MTU is now obtained from the interface and OVERHEAD is added to it.
  Defaults to 1518 as this appears to be the packet size for the qdisc.
  This value is now used throughout for all calculations
* more error handling

README.md

@@ -67,8 +67,6 @@ If it's working the output from tc should look something like this:
      maxpacket 1518 drop_overlimit 0 new_flow_count 5081 ecn_mark 0
      new_flows_len 0 old_flows_len 1
 
-
-
 ## Known bugs, limitations
 
 
@@ -77,8 +75,8 @@ If it's working the output from tc should look something like this:
     * No marking or traffic classification is currently possible, this also means that DSCP squashing does not work
     * ECN marking is not supported
 * The script does not does anything with the Link Layer Adaptation fields. 
-* On kernel 5.10 the script does not remove the nssifb interface if it's stopped, because removing or even bringing down the interface frequently crashed my router. This could cause problems if you're switching to a script which set up regular ifb4ethX interfaces. You probably need to reboot if you want to switch to another SQM script. On kernel 5.15 this problem has been resolved. 
-* In some cases, the router crashes on ip link up of nssifb, *especially* when called from hotplug. Because of this, there's workaround in the script that prevents the script from executing when it's called from hotplug.  
+* On kernel 5.10 the script does not remove the nssifb interface if it's stopped, because removing or even bringing down the interface frequently crashed my router. This could cause problems if you're switching to a script which set up regular ifb4ethX interfaces. You probably need to reboot if you want to switch to another SQM script. 
+# On kernel 5.15 the above problem has been resolved, but in some cases (I think under high load), the router crashes on ip link up of nssifb, *especially* when called from hotplug. Because of this, there's workaround in the script that prevents the script from executing when it's called from hotplug.