I have tried Googling all kinds of wording and a lot of the results are outdated. Most discuss the lvl25 Boost still being available and whether the incoming lvl40 Boost would unlock Subclass nodes. All the official descriptions mention is the fact that the lvl Boost can only be used on a Character [b]below[/b] the lvl the Boost will reach, and the Subclass boost only working with a [b]blank[/b] or [b]partially unlocked[/b] Subclass. I took some -Bl00-D4M-ING- baaaad advice from another player to boost a Hunter Subclass for PvP rather than attempting to boost my new Warlock Subclass when I unlocked it. [spoiler]Basically I'm feeling pretty blue about it and rather sheepish when it comes to paying for another booster pack in case it doesn't let me.[/spoiler]