The "deal" on the blade pivot "tension" screw is than it does not exist. The screw is not intended to be a method for adjusting tension. As you've already at least part-way realized, the opening "tension" on a properly assembled front lock is a factor of lock spring strength, all you can possibly increase by over-tightening the pivot is drag, which will make the knife both difficult to open and difficult to close.
The trick is to tighten it slowly until you feel drag, then back it off until the drag just disappears. Same applies to the lockbar pivot. Loosening either, or both, any further will only increase blade play, the pressure of the lockbar against the cam on the blade tang, and thus the perceived opening tension remains a constant.
The only safe and effective way to lower opening tension "sometimes" is to disassemble the knife, examine the bottom surface of the lockbar dog and the cam surface of the blade tang, and carefully polish them to an absolute mirrror finish if they don't already have one. Even here, you are not really adjusting "tension" merely minimizing the friction of the dog riding on the cam, but if they are not perfect, it will make the action feel lighter.
The only real way to lower blade tension is by "tweaking" the lockspring. Not a good idea, in fact a really bad one, as there is a substantial risk of increasing the risk of the blade opening far enough to bite you while in your pocket to an unacceptable level.
