Ok, so, it is generally accepted (and possibly even RAW-correct) that you can stack metabreath feats (Draconomicon) with themselves on a single breath attack. For example, you can use Enlarge Breath twice to turn a 50-foot cone into a 100-foot cone in exchange for increasing the recharge time by +2 instead of +1.
Do you see the problem yet?
Consider that there is nothing preventing you from stacking Enlarge Breath on your breath weapon a billion times, and therefore blowing up most of the world (or all of it, depending on the world shape involved and your location on it -- if all else fails, you can throw on a couple uses of Split Breath and breathe in four directions simultaneously), at the low cost of never being able to use your breath weapon again.
That is, to say the least, a little silly.
The obvious solution is to say no, you can't stack metabreath feats with themselves after all. (This is probably the real intended solution, considering metamagic feats stopped being stackable with themselves in the 3.0-3.5 changeover, so metabreath feats should have, too.)
Or you can say you can, but you can only do it up to 3 times or 5 times or your Constitution modifier times or whatever.
But today I had a better idea: You can take metabreath feats more than once, and you can stack them with themselves as many times as you've taken them.
This is better because soft caps are always better than hard caps.
