Thanks for the reminder about this. I was able to build a proof of concept that would cause HL to "stop" adding in BAB/Save values once it hit 21+ Class Hit Dice.
I would need to talk to Colen to see how or if I would be allowed to add this. I think "maybe" if there was an option to turn this feature on/off. My fear is that if I stopped this cold after 12 years of d20 always adding BAB/Saves after level 21 I will break peoples stuff.
But if this was an Option you could turn on/off then maybe I could get it in. So its a "good" news sort of thing.
