Auto Focus Arm bumping heart keychains (ZATH0X)

We have our auto focus arm taped (as suggested here) and we're running into problems with the ZATH heart key chains as the arm is frequently catching the foam jig and causing it to move out of place and also bump the auto focus arm askew.

It seems that the foam jig is possibly too deep. We had a spare jig which we tried swapping in but that hasn't solved the issue. We also didn't notice this issue before the arm had to be taped into place. It doesn't seem like having the auto focus arm taped should affect this however the timing of this issue starting only after that occurred merited mentioning it.

Has anyone else experienced this? Can you suggest any solution for this? We've tried trying to leave the hard key chain higher up in the jig but it gets forced down when the auto focus arm pushes down at the beginning to focus.

There's a number of factors here for what you're seeing. To address the focus sensor tape fix, my first question is if the two parts that you taped (the hexagonal piece and the black cyclinder that attaches to it) are taped so that the pieces are in solid contatct with each other. If there's a small gap, it will compress slightly during the focus process but decompress back out, hitting the jig during the run.
The next thing I'm curious to know is if it is hitting the jig itself or if it's hitting just the small metal ring that attaches the keychain to the main large keyring. That small ring sits up a bit higher (often above the jig surface; it can difficult to get the ring to lie down flat). If it's only contacting the ring, you can carfully bend the ring with pliers to remove the ring before running the job.
You say that you tried to leave it sitting higher in the jig but it got pushed down as the sensor contacted it; The next thing I have to suggest is to put something very solid and approximately the right size under the keychain in the jig. The best thing might be a second keychain (with the small ring removed) as it's about 0.04 inches thick and the jig is about 0.125 inches deep, bringing you about about a 1/3rd of the way.
I'm somewhat inclined to think it's the first of all these things since you say this problem only started occuring after fixing your sensor.