JCM kick in on specific value

ManifoldFaces

Help me out because those keyed stuff aren't working like in other softwares. 

I want morph on 0% at X -70 and 100% at x-110.

So i key 0% on x0, 0% on x-70 then 100% at x-110. Then ERC Freeze and Check Keyed Extract from play range. 

I end up with 50% morph at x0 witch just blows my head off. Other results are even worse like 100% at x0 or 100% at x180.

 

EDIT i just used propety hierarchy and fixed the values and this damn thing finally works. But i still don't get how keyed ERC works.