New player with simple question regarding level caps

[Iscah]

it's not that OP was worried about overlevelling it was that he wanted to experience the game like as if it was coming out one expansion at a time. he wanted to be capped and then do everything that was endgame for that expansion at that level cap and then move on when he felt like he was ready to activate the next part to do so.

I don't think so. Rather he wanted to have the level cap for each expansion so he wouldn't keep levelling higher than he was supposed to be (eg. can't go beyond Lv60 until moving from HW to SB). At least that's how I understood it.

But as others have said, the only way to achieve that is to share the EXP around between multiple classes.