Inchoroi
Adventurer
Minor nitpick: While Rise of Tiamat erroneously referred to story-based advancement as “milestone leveling,” it is not consistent with how the DMG describes milestone XP, which is essentially just XP awards for stuff other than encounters. I actually think milestone XP as described in the DMG is great, and award it for completing quest objectives.
Unfortunately, nobody reads the DMG and Rise of Tiamat’s misuse of the term “milestones” has become standard in common parlance. I try to use the terms the way the DMG does to set an example, but at the end of the day I’m probably just yelling at clouds.
I get that; I nitpick words a lot, too!
I will state, however, that I've been using the words "milestones" with regards to leveling since 3e days; I believe I picked it up from my first DM, not even in an actual D&D game, but a different game entirely.
Looking back on it now, its crazy how much my first DM shaped my DM style. Explains a lot, as he killed my very first character the second session I joined the game.