I tested this by buying 6 Butterfly items on my morphling (including the lvl25 multistrike talent) and then testing it on a group of enemy heroes (custom lobby).

Even when i Attribute Shift every stat i can into Strength my Adaptive Strike (Strength) stun duration is barely above 1 second - while the tooltip shows it can go up to 3 seconds.

The tooltip states " If his strength is 50% higher than his agility, the maximum stun/knockback is dealt." but for some reason it takes into account the bonus agility (from items) into calculation which you can not Attribute Shift.

Frankly i am not sure this is working as intended - it makes no sense to me that stacking multiple agility items will make your Adaptive Strike (strength) pretty much worthless even when you choose to Shift all base points into strength.

To me it seems that the "strength above 50% higher than agility" calculation should only take into account Morph's BASE stats (not from items) so that he can fully control does he want maximum stun duration by Shifting all points into strength.