i think most people with a charger know how to tighten belts - no need to take the headlight out either - you can do it from the top.
Having taken about 20 or so chargers apart I would have to say that oil and dust - or dirty oil, act as a cutting compound just the same as ptfe and dust. If anything the crap from the crankcase in oil vapour is even more effective at grinding.
Key to a healthy charger in my opinion is regular oil changes (i do mine every 3,000 miles) for the bearings and if you dont use boost return - oil vapour system - and decent filtration (i use paper filters, changed every 3,000miles).
I think part of the reason for their boost return mod (personal opinion) is
1. PSD were a competitor who suggested this - and g-werks who do it now are.
2. It shows up a lot easier when charger oil seals are weeping, so they'd probably have a lot more returns under guarantee. With the boost return in place you dont see this weepage as the oil goes back in the charger. With boost return it goes on the suspension turret.
ps - i've seen a number of jabba serviced chargers with oil seals, apex seals and bearings which don't appear to have been changed!!