There is more to it than that.
The ALH and BHW use Garrett VNT turbochargers, two different ones. They rarely fail, and last a good long time. I'd say as long as any turbocharger could possibly last. ALH units can get sticky due to driving them too easy too often, but that is driver error, not the mechanicals. You drive the car normally, they'll hold up just fine. Only BHW turbos I have ever seen fail were ones that starved for oil when the balance shaft chain was allowed to fail, and the oil pump quit turning. Otherwise, they hold up just fine.
The BEW and BRM use Borg Warner VNT turbochargers, two different ones. They have a vane sensor in the actuator that sometimes can fail, and is not sold separately, but can be tuned out, it is not needed for the ECU to do its job (the BHW gets along just fine without them). The BRM turbo specifically has an issue, much more so than the BEW, where the rod stop simply wears out, and causes the VNT to over travel. The "zip tie mod" is a band-aid fix for that.
The CBEA/CJAA turbochargers, also BW units, sometimes have the vane sensor fail, but this is available as a separate repair kit, but they also suffer from the super high EGTs associated with DPF regenerations. That is the only reason they fail, and that frequency is all over the place. The CKRA engines, again a different unit on a different engine, are especially fragile, and had an extended warranty and an updated design to deal with the fragile nature of them. Not sure what specifically the problem was with those, and in theory since those are SCR engines that should not be subjected to as much DPF regen as the others.
In any event, a delete on any of the CR engines will mostly eliminate any extra stress those turbochargers would endure. I have deleted customers with over 300k miles on there CJAAs and still going along just fine on their original turbochargers.
And, unlike the older A3 cars, no giant rust holes in the bodies, either.
