> The hypothetical here is whether you market something as a "50 mbps" service with the caveat that it's best-effort

It's already been explained to you that the "unlimited" plan at issue was clearly not best-effort after the limit was reached. The throttling that Verizon applied was around-the-clock and resulted in the fire department's device getting a tiny fraction of the speed that personal devices at the same location were getting. The throttling was not happening as a result of congestion, it was an artificial limit on a plan advertised as "unlimited". All theses arguments you're making about best-effort service are irrelevant distractions. A plan that stops being best-effort part way through the billing period cannot be honestly sold as "best-effort" any more than it can be honestly sold as "unlimited".

I'm fine with selling a 50mbps best-effort plan as "50mbps". A "200kpbs plan with 50Mbps bursts" is not that. If you are throttling people to 200kbps after a short burst, that is not best effort. A best effort plan would vary with the overall congestion, it would not drop off specifically based on your personal use of the connection.