Bare with me here.
I actually know quite a bit about both automotive clearcoats and pinball/playfields.
The truth about all this debate is really simple.
No one really knows why this is happening to these newer playfields.
You can guess and if you are well educated on both you can make an educated guess but what is really needed here is this.
When chemical manufacturers test products they are going to release they have chemist or scientists in a lab that analyze these products and the failure points as well as the suitability of products for the intended purpose.
Through those studies and experiments they gather data on the formulations ,problems that arise and ways to solve them.
This is what seems to be lacking here.

A good scientific study would definitely uncover the issue and help solve it. Anything less is just guessing educated or otherwise.
Is it the ink adhering to the wood?
Is it the clear not curing long enough?
Is it the clear itself?
Maybe the digital printing?
Give it to the right lab for analysis and we can find out.
Nothing crazy or far fetched about the idea. It is typical in most manufacturing or chemical compound settings
Pinball manufacturers might have to adapt for a short time to hone in on the best products and protocols to use moving forward to avoid these problems.