I heard about people adding a bit of high performance 2-stroke engine oil (example Blenzal, Klotz, Amsoil) to their tanks.

This small amount of oil could helps lubricating fuel system, combustion chamber, valves, piston top, etc.

If anybody knows, have experience with, agree or disagree, please comment.

 

only helps if you have a rotary with the injection pump removed or some two stroke engine with no real lubrication system

The design of the piston powered internal combustion engine relies mainly on the crankcase oil to lubricate the cylinder walls under the piston. The top end lubricants blended into gasolines, at least those in major metropolitan countries, does an adequate job of lubricating the top end