So iFixit explained the jelly effect and also said that cheaper display panels show it more visible than higher quality panels. So I guess Apple uses different display manufactures and some are of higher and some are of lower quality.
Jelly effect is there but some have no problems and some have big problems with it. A user posted a video of his device here, also has touch issues with the display, and I can see it clearly there. Not on my device. And I find my Mini 6 display to be quite nice. Similar to the higher LCD quality of my Mini 5 but more accurate colors as my Mini 5 had major red tint compared to my Mini 6. Some users here are also reporting about bad display quality compared to the Mini 5. Not with my Mini 6.
So maybe if someone really really wants the Mini 6 it is worth it to try different Mini 6 to maybe find a device with a better display which doesn't show jelly that much, even though it will be there on every device.
Jelly effect is there but some have no problems and some have big problems with it. A user posted a video of his device here, also has touch issues with the display, and I can see it clearly there. Not on my device. And I find my Mini 6 display to be quite nice. Similar to the higher LCD quality of my Mini 5 but more accurate colors as my Mini 5 had major red tint compared to my Mini 6. Some users here are also reporting about bad display quality compared to the Mini 5. Not with my Mini 6.
So maybe if someone really really wants the Mini 6 it is worth it to try different Mini 6 to maybe find a device with a better display which doesn't show jelly that much, even though it will be there on every device.