Ok, thanks. Since it's a relatively short time duration and a simple assembly, I decided to do it frame by frame in the following manner: I made a family table of the part with the flexible dimensions as the vaying parameter. I then assembled every instance of the family table to the same coordinate system. Now by changing the component visibility during animation, I simulated the component flexing.
It was still time consuming to assemble every instance to the same coordinate system. How would I write a mapkey that automatically aligns coordinate systems of a new component to a component already in the assembly? Every method I tried, the mapkey paused for user input.
Thanks for your help!