Intake cam chain play

I noticed the intake cam chain (part #6) tightens and loosens when I manually turn the engine over. I'm aware that chains have tight spots but when this loosens up it's hits the chain guide that goes overtop (part #14). If I adjust the cam chain tensioner once the engine is idling (part #11) will this be 'fixed'?

I took the engine off and did an overhaul because there was a knocking noise and this was the only issue I found.
Additionally, the tensioner bolt was stripped (this has been fixed), could the issue just have been the bolt? I really don't want to put the engine back on the frame without having the certainty.

Is it possible that one of the cam chain sprockets is backing off of the cam?

That's a pretty short chain, so a visible change in tightness at that slow of a rotation speed would mean quite a bit of stretching.

If it were my bike, I'd just replace that chain. It's not terribly difficult to remove both camshafts and swap the chain, but it is tedious and you have to be very careful to get the timing correct when reinstalling.