There should be no affect on forgiveness. If you have a swing that is fast enough AND you have a late release, the softer tip can certainly add dynamic loft and needs to be fitted. However, without both of these swing characteristics, there is little dynamic loft added by the shaft flex: the shaft is more or less straight at impact. As Release suggests, if you are looking to affect your ball flight, including launch angle, do that by adjusting the loft of the head.
There are two primary effects of a soft tip:
a) it creates greater sense of loading of the shaft, which will affects the the player's tempo and his/her timing of the transition and release. The degree to which this sensation is added, in my understanding, depends on the stiffness of the tip section relative to the stiffness of the butt section.
b) it will affect the feel at impact -- a tip that is too stiff for the player can feel "harsh."
I think it is the first of these that Release is referring to when he discusses the unloading of energy. This "unloading of energy" is actually the gains that result from shaft flex encouraging/facilitating good tempo, transition, and release. I don't think he is talking about releasing energy from the shaft flexing "into the ball." There is actually VERY little, if any, added "kick velocity" resulting from the shaft flex at impact.