I followed Tom Lawrence's tutorial on setting up FQ-Codel to correct buffer bloat ( https://www.youtube.com/watch?v=iXqExAALzR8 )

I'm on a cable connection - nominal 500Down/20Up. Before FQ-Codel I was often getting 10-15% higher numbers from dslreports, but with bad buffer bloat. Now I'm getting results that look like this pretty consistently:
So it appears as if I've got things working.

I am periodically getting bursts of these message showing up in my logs: (sometimes just one - never seen more than 4)

config_aqm Unable to configure flowset, flowset busy!
config_aqm Unable to configure flowset, flowset busy!
config_aqm Unable to configure flowset, flowset busy!
config_aqm Unable to configure flowset, flowset busy!

Is this an indication of upstream network congestion, or that I have FQ-Codel improperly configured?

Here's the contents of /tmp/rules.limiter

pipe 1 config  bw 500Mb queue 3000 codel target 5ms interval 100ms ecn
sched 1 config pipe 1 type fq_codel target 5ms interval 100ms quantum 1514 limit 10240 flows 1024 ecn
queue 1 config pipe 1 codel target 0ms interval 0ms ecn


pipe 2 config  bw 20Mb queue 500 codel target 5ms interval 100ms ecn
sched 2 config pipe 2 type fq_codel target 5ms interval 100ms quantum 1514 limit 10240 flows 1024 ecn
queue 2 config pipe 2 codel target 5ms interval 100ms ecn

Only thing I played with was queue -- 3000 Down/500Up seemed to yield consistent results--but I really wasn't sure what I was doing.

Do these messages indicate I should make some adjustments, or should I take the approach don't try to fix what isn't broken?

Thanks in advance for any suggestions/input.

Aside:
(Sorry for the noobish question, but It's really hard to find good information that is at the right level - stuff is way too basic or way too complicated.
Since I'm applying enterprise grade techniques to a residential network I don't need / want to wade though all the stuff about load balancers, redundant routers, failover etc, since I am never likely to see any of that technology and won't remember it anyway due to lack of use, and if I have to skip though another "this is binary/IPv4 subnetting" I'm going to vomit! Any suggestions on how to get what I need in an efficient would also be appreciated. )