Worth changing 4.0L timing chain as preventive maintenance?

I'm assuming that after 22 years and almost 200k miles, the timing chain in my 93 ZJ has probably got some slack in it. I'm not getting any obvious performance issues or CELs or anything like that, I'm just working on the balance of probabilities.



Part of me wants to get in there and change it, but the since the Jeep runs OK at the moment, is it actually worth me going to that effort?



And does anybody know if this test for timing chain slack is valid for the 4.0L engine?

Testing for timing chain slack

Testing for timing chain slack