Take the Lama Kensai tree as another example. See screenshot below which I will reference:
Let's say I wanted to build an axe wielding monk to take advantage of One With The Blade, which *sounds* like a cool new possibility, a good idea. But I have to unlock that top tier right? I selected all the enhancements wanted and needed just to reach the next to top tier, and spent 26 AP. I didn't really want Reed in the Wind mind you but you made me take it just so I could unlock stuff in the next tier up. So I'm already down 3 AP wasted. But that top tier requires 40 AP spent in this tree. So you're forcing to me to waste another 14 AP in stuff I don't want to get to the fun stuff that I do want.
And you know the idea of an axe monk may be silly so lets even skip OWTB and say I just wanted the crit rang enhancer, Keen Edge. Same problem! I still am short 14 AP just to unlock the damn thing. But my build may not want tactics, or dodge, or critical accuracy, and so on. Tactics and dodge are not inherently bad enhancements for all builds - other builds may want them, but mine doesn't. Yet I still have to waste AP on stuff I don't value for this build because you gated the top tier at 40 AP. Those enhancements aren't even the capstone! The capstone is on the bottom row available only to Fighter level 20.
How this should work:
Get rid of AP/Tier gating. If you feel One With the Blade or Keen Edge are so powerful that I must be a higher level character to use them, then give them a Character Level requirement in addition to the long prerequisite line already in place. Make me be level 15, 18, I don't care. But don't make me waste up to 14 AP on things that don't look fun to me, so that I can use them in a different tree on fun stuff for my goofy axe monk. Character Level is a perfectly good way to gate power while keeping the build process across multiple trees flexible and fun the way it is on Live.
What does AP/Tier gating do for this system that Character Level, Enhancement and Feat prerequisites can't achieve, other than needlessly constrict build variety through wasted AP as well as add complexity?