What I have noticed after some online research also is the ticking issue is almost never solved permanently by repairing / replacing lifters but a cylinder head change. That brings camshafts and valves (and springs etc.) into question as well as blocked oil lines inside the cylinder heads..
Here is a link about some solutions to ticking issues..
https://www.e90post.com/forums/showt...t=13504&page=1
That is from e90 posting (not e53 m62 4.4) but there are a lot of similarities..
Cheers,
Ozzie