I've experienced both:
Mata Hari - hardtop installed March 2019. Original artwork sanded off. No clear coat applied before hardtop install. 18 months and several hundred games later, still looks and plays like new.
Eight Ball Deluxe (Attempt 1) - hardtop installed May 2020. Original artwork sanded off. No clear coat applied before hardtop install. After 2 to 3 weeks, hardtop developed 4 significant areas of "lifting" (bubbles) ranging in size from a square inch to several square inches.
Eight Ball Deluxe (Attempt 2) - first hardtop removed (that was an adventure!) and 2nd one installed in early August 2020. Playfield re-sanded after ink and adhesive residue removed. Three light coats of rattle can Clear (Rustoleum) applied with a week of outgassing allowed between the last coat of clear and the hardtop installation. So far, after nearly 4 weeks and 100+ games, no issues.
Outside Edge was outstanding with their prompt help, support and recommendations - they took care of me and my situation, and they still have a happy customer.
While it was huge pain to re-do the hardtop, it did give me the opportunity to do some stuff I had thought about doing (but did not) the first go around:
- Totally disassemble the three pop bumpers, ultrasonic clean and tumble the individual metal parts, and reassemble with new springs and coil sleeves
- Put in Molex connectors for all of the coils allowing for quicker reinstall and easier future maintenance for when assemblies need to be removed