said by thorin:
In most if not all markets Powerboost is disabled on DOCSIS 3 modems.
Powerboost is enabled in the config file for the speed tier, not the modem. The top tiers, which require a DOCSIS 3 modem, do not have Powerboost enabled, whereas the lower tiers do. Powerboost will work, as long as your tier has that feature, regardless of modem type.