I agree it would be difficult to get anything significant from joule creep in an AEG, but it's still possible to get a benefit from it, even though a little.
I have read some technical threads on overvoluming AEGs to produce certain effects. Done right, it's not insignificant. but we're not talking a magical half a joule either.
I futz with V2s, V3s and V6s. I could be wrong... but probably, most likely not, as far as I know.