Removing valves 1.9 tdi ALH Lump, which ones to bypass.

I see alot of talk about bypassing valves etc to tidy up and remove unreliable parts etc, and smooth power delivery.

I just wondered which if any valves on the 1.9 tdi alh NON pd engine could be removed? I can find the tutorials no bother, but dont know which ones are pertaining to this engine.

Any help appreciated Cheers