They might ghost. They might not. The safe play is to order non ghosting.

My experience is LEDs as GI above the playfield just don't look right on EMs. Inserts are a different story. It just depends. You have to try them and see. So much of this is personal taste.

If you are going to do it warm white is a better look.

Well I've had them in EMs and they ghosted so I'll disagree here. They don't always but they can.

I'm no electronics guy but my understanding is there can be enough flow of current that isn't enough to light an incandescent but is enough to flicker a LED before it collapses. I would assume something like what you get with EMF on a coil.

It doesn't always happen on every feature lamp
But it does happen.

I just installed a green LED under the double bonus insert on my Old Chicago. The incandescent was dim and I wanted more pop. That light is lit by the ball count unit stepper. It really pops now and no ghosting. I put them in a different Bally game and they did. Only way to know is try it.