2.0 tfsi 200 problem lost hope :(

Hey all I have an Audi A3 2.0 tfsi quattro sportback
Believe it is the BWA 200bhp engine

The problem started when i noticed the rev limiter took longer to come down back to idle
The car misfires and vibrates and has a really rough idle

No fault codes showing (apart from a camshaft sensor one which after cleared never came back on)

The mechanic has had the car for 3 weeks and assured me its nothing electrical and the problem is mechanical

He believes it has something to do with the cam lobes and that they have worn even tho he hasnt checked yet....
The car has done around 100,000 miles
the timing has been checked and that is all fine
no fault codes

The VCDs showed the boost reading higher than it should be on idle

any ideas?
im sorry if thats really vague but i dont know

Yeah exactly my point i decided to do my own research to and narrowed it down to a few things. I believe that this "mechanic" that i got reccommended to go to is just being lazy as he stripped the engine to check the timing and put it back together...Hes leaving me with the decision to make which is "ill strip and check the cams but your gonna get charged more" and the other option which is rebuild the engine. I think i might take it elsewhere.... The main issue these days is finding a genuine mechanic who is honest thanks for your help anyway as for the guy who said get an A7 3.0 tdi that really helped me diagnose my problem with my car kudos to you sir