Questions about custom GBA screens flickering

Hello,

I got interested into FunnyPlaying laminated screens (ITA and IPS) to upgrade my GBA display, but after watching some reviews a certain problem about what should be transparent on screen is flickering instead was pointed out. I don't know much about the technical details, but from what I understand two different images were used to make some sprites look transparent and with modern screens we see what we couldn't see with screens from before.

Are every custom GBA screens subject to this problem? For people using these screens, have you ever noticed this problem? Thanks for your help!