Read through all of this. So if I understand correctly, MAX Kamehameha is just the basic Kamehameha at full power and the Super Kamehameha is an enhanced version of the technique, and based on previous scans Piccolo Junior (who is around Goku's level) managed to endure a Super Kamehameha and come out of it without a lot of damage? As in:
- Super Kamehameha is a superior version of Kamehameha and is shown to multiply the user's power level by around 3x (Against Raditz)
- MAX Kamehameha is just the full power of the basic Kamehameha
- Roshi blew up the moon with a full power basic Kamehameha
- Piccolo physically handles the power of Super Kamehameha from Goku despite being around Goku's power
Which all implies that the physical stats of the user are not that much lower than their usage of MAX Kamehameha, let alone Super Kamehameha. Meaning they should scale to a similar level, close enough that Roshi could endure his own MAX Kamehameha in the 21st Budokai. In other words:
- Super Kamehameha (3x Goku's Power) > MAX Kamehameha (Less than 3x Roshi's power)
Then on top of all that, Roshi's power was apparently 139 at the 22nd Budokai and 180 with the Kamehameha, equal to Goku and Tien's base powers at the 22nd Budokai.
At this point I don't see why I wouldn't agree with the upgrade. It's clear that the user's physicals aren't dramatically lower than the Kamehameha's power, close enough that the user can survive their own Kamehameha if fired back at them.