I've never ever had a car with that type of engine in it, though almost bought one - a used Audi A1, for my wife, and changed direction and bought her a new factory order VW Polo 1.2TSI 110PS for many reasons unconnected with that engine engine/gearbox. Later on, when finding out about that brilliant but shockingly flawed engine's traits, I considered that I'd dodged a bullet!
My question to you must be, why take a chance when there are many other bigger and with similar output power/torque VW Group engines out there - even if these other engines might have similar but fixable potential issues.
Now if you just wanted to own/run a car with one of these twincharger engine as a second or third car, then yes go ahead, but if you want/need a reliable car, why take the risk, as you know that as far as I know, no quality/safe engine reconditioner handles these engines - and for good reasons, ie they can not support any expected warranty that a properly reconditioned engine should come with.
Early DSG gearboxes, it seems like they are fixable and well supported, but make sure that you include a full rebuild into your car ownership costings.
From my maybe twisted way of looking at things, VW Group, and other car builder groups, introduced that type of engine as the way forward to reduce petrol engines emissions and in general start the trend to "down size" engines while losing nothing, and gaining MPG, what actually happened was, as I commented on this at the time, a more expensive, heavier, bigger in installation "volume", and much more complex engine was created - that meant that users ended up with cars being off the road for extended periods in time and VW Group had to in some cases, foot the repair bill, then VW Group dropped that engine type very quickly - so how much of that makes any sense or good reason for buying a used and maybe "sorted out for the time being" car with that engine in it, especially one that is now quite old and will never get any "good will"
help from VW Group.