This'd only FURTHER devalue the meaningfulness of epic levels, which was, if nothing else, one of the more vocal points made.
It entirely avoids any of the concerns I've been taking part in discussing, so I'm assuming you're approaching another concern altogether.
However, even removing those concerns in question from the equation, I'm afraid I'm not seeing the merits of this suggestion- and dramatically so with the concerns included.
The points made in opposition to this (including xp farming concerns, the possible lack of desire to even run with toons 5 levels lower at 25, and how it'd break further epic level xp elements if the last 5 levels were ever added) are perhaps more potent than the ones in favor for it.2) Remove any level deltas ... basically, let 20s run with 25s without penalty. I realize this may mess with the "epic n/h/e" mechanics.
Now you have a system in which folks have to regrind the levels, and they're down a little from folks who stayed at the 25 cap, but they can group effectively. The delta between a 25 who stayed at cap and a 20 who didn't becomes +3 BAB/+2 Saves/2 Feats/1 Stat up ... and the 20 doesn't feel like they have to play the narrow level range/quest game on the way up.
Still, your latter points have merit: Epic levels ARE supposed to be about broad horizons and feeling powerful. So being confined to narrower questing does seem more troublesome.
While your numbers may perhaps (hopefully?) be a bit inflated in favor of your point, you have a very solid argument.
Unfortunately, that's not a matter I have any recommendations for.
Yes. Bonuses and Tomes included, my TRs are leveling faster than my first lifers used to, back when.
Lets assume a minimum 30% decrease in xp due to these bonuses, as well as Floyd's decrease (and Ninety's projection of 10%, and a favorable average of his epic level xp range projections at 3mil):
Original 3rd life xp reqs: 4.378 mil.*
Current xp equivalent: Aprox. 2.626 mil.*
-10%: 2.363
Proposition's somewhat favorable projection: 5.363 mil.*
While Ninety's point is reinforced, the actual increase is 'only' 25%.
..then again, considering how long a third life used to take, that's a hefty increase.
Someone using all of bravery and tomes and ship buffs and votm would likely be able to narrow that further- but given their exclusion from epic xp, not by very much.
Given comparison to current xp requirements, it's near exactly double the expense.
So for now, the proposal doesn't seem to work very well.
*About the numbers: I assumed a 40% decrease in xp requirements. Considering an average of about +40% bravery and just +20% tome, we're left with 59% base xp. Rounding against my argument brings it to 60%.
Constant use of elite bravery and greater tome will notably lower that even further.
Edit: Forgot to add in the 10% projected decrease, fixed.