I have been a early pioneer of uv inkjet production almost 15 years ago. Being one of the smallest individual producer of early restorations of original playfields back then (everyone else believed that individual screens had to be done) & the last 8 years towards new playfield reproductions of Star Gazer & Seawitch. Never had pooling or uv ink delaminating off the surface of the playfield in over 200+ playfields original or new. Here is the info I have learned over the years. I have talked to a number of pinball manufacturers over the years about pinball production.

Do not rush your production! Playfields need a good clean base to start with before sealing the wood (I do 2 coats of Varethane water based gloss). Make sure you never finish clear if you can still smell the ink! Do not rush finish clear coats! The best way would be to do only 1 coat per day, or make sure you have enough time before doing more clear. Playfields should be ready to install in 1-2 weeks after finish clear coats. I personally like the finger nail test in the bottom apron area of the playfield. Kind of low tech & not a fancy term for seeing if the surface is hard & ready to populate.

My latest clear guy does a weird finish clear coat system of production. Quick hardner coat, & then 2 good coats of Omni (old stuff not water based). He also leaves the inserts installed in the rollovers during the process, & they are sent to customers still there. So far 95% do not need any cleaning, & if they do you can use a tiny knife to clean the insert & rollover.

Black ink is the weakest link if you go heavy or fast on your finish clear coats. I had a Stern CSI playfield delaminate so this has been going on for years. Plywood has changed over the years, & likely not as good as pre 2000.

Any manufacture or playfield producer can feel free to contact me for more info. I have openly disclosed my playfield process over the years.