The only 2 frame locks that I needed to 'learn' opening were both ZTs. 450 and 452. They DON'T like any pressure on the lock bar. With the 452 all that is needed, for me, is to put my middle finger in the cut out. With that position I can push all I want and the knife will fly open every time. The 450 flies open with middle finger on the clip.
I kind of enjoy 'learning' a new knife.
Don't give up, if you love the knife, you'll figure it out.
Joe