Lifting the needle makes the mixture richer. If you lift it too far, the carburetor will flood, which will be pretty obvious if it happens. However there is something wrong with the process if it measures 4 to 5 mm down, and runs as well as you had it running initially. You didn't by any chance put the lever in upside down the last time you assembled it, did you? The spring end of the lever has a feature to center the spring, if you have it the right way up.
Using different L and H settings will not hurt anything, but needing to use them tells you that your metering lever height setting is wrong. If you need to use a lot more than about 1 1/4 turns it tells you that you have the needle too low, and if you need to use a lot less it tells you that you have the needle too high.
