Prathman, what you describe sounds like adapting to a pre-existing condition. If so then the usual rules do not apply. I've had to do that too to make do with a part on an old bike that I was just fixing up. But it's not a good situation depite your success so far.

I may have also been a little overboard on the spec for 2 lbs of push at the fork leg to get it moving. But for lower to mid quality headsets I'd still want to see from 1 to 2 lbs of grab before the fork wanted to move. But the key is that when moving the travel should be easy and smooth with no notchiness or other signs of distress. If there are any then there's no option but to lighten it up a little if that fixes it. If it doesn't get any smoother up to the point of being too loose then I'd sigh and set it with some preload and expect it to either live or die as fate decrees. But under no circumstance would I set it to just barely no play since that just invites the risk of the bearings losing contact with the races and putting all the load on only one spot up top and one below. Bearings that are too loose and suffer from loss of ball or roller contact are a major reason for early bearing failure in cartridge style bearings. And it's no different with our situation. I'd rather put in a little too much preload than not enough as I said in my earlier post.

Mind you who knows what the dynamics are in a typical headset, head tube and steer tube system? It may well be that the whole thing is self balancing or some dynamic when riding is actually making the headset bearings tighter instead of just levering fore and aft. If that's the case then just setting to no play is fine. Or it may be that some bike and fork combinations tend to tighten up the axial load in use while others loosen or perhaps even just stay neutral. Without some fancy strain guage engineering test it's hard to say.

I'll close that in the last 15'ish years of setting all of around 25 to 30 headsets up that I've done I've always set them for some preload but also for a smooth rotation. And unlike your experience all of mine have survived and those that haven't been sold off are still going strong with no sign of any indexing or other issues. So it would appear to be a case of YMMV. And then there's the thought that when you set it to just no play perhaps you're far enough on the tight side of "just no play" that you're putting in an amount of preload that isn't that far from what I'm suggesting after all.... <shrugs>