You want to hear clatter from that area. Don't try to make it quiet.
This engine is not supposed to be quiet.
The iron barrel engines never had adjustable spindles, and never needed them, either. If you want to know why these adjustable spindles are there, it's because the India home market customers are generally "technologically challenged" and seemingly obsessed with making their bikes quiet. So they put these spindles on there in order to allow yet another way for these owners to destroy their engines by incorrect adjustments. This typically goes along with the obligatory too-tight valve adjustment that goes on on India, trying to quiet those down and causing burnt valves in the process.
If you go in there and mess with that stuff, you are more likely to do harm instead of good. Just let it be.
If , for some reason, it has come loose and flopping around in there, then you have to adjust it. In that situation, seek out somebody who can tell you how to properly adjust it, or will do it for you.
The general rule with Enfield valve train clearances is that in most cases looser and louder is better.