Problem is, Whites had significantly more than just a Datajack, check out RA:S 
True, but Puck was brought in from the outside as a true-believer, instead of a convert like many of the other Deus-babies. So, there's nothing to say that he had to have the augmentation done.
Again, this is addressed in RA:S, page 82 to be precise:
The standard package for Banded consists of: BTL Stimulator, Carcerand Release Receiver, Commlink 8, Cyberears (Hearing Amp, Select Filter 5), Cybereyes (Thermo, Low Light, Flare Comp, Vision Magnification 3), Invoked Memeory Stimulator (alphaware), Snake-Eyes Link (betaware)
Otaku not created by Deus do not get the BTL Stimulator and IMS
All Whites additionally get a Datajack 4 w/ ASIST Conver and Cerebral Booster 2
A 5-Band White additionally gets: Headware Memory (300 MP), Math SPU 4, Encephalon 3
All in all, the standard 5-Band White is at 1 Essence. In later books the implants and Essence costs underwent come re-adjustment, but all in all a high-ranking otaku won't have more than ~2.5 Essence. Deus liked to keep his little toys under control, and why would Puck have refused a gift from his god which improves his abilities?
Also, Deus might have known that those with "true" abilities would suffer from Essence loss... *shrug*
Back then, otaku didn't care about Essence loss.