I'll move this to the texture dropper suggestion, though we do have a separate color dropper suggestion (This one is easier and more likely to be implemented)

Upvoted, but there are several similar other requests on the same request, this might get rolled in with those soon. I suggest you look for those and give them an upvote, too.

Please work on this soon!

Absolutely. This is my #1 ask.

As the painting on one of the layers is always directly merged into the layer, and there is the possibility of additionally merged brushes, it's impossible to really grab the texture used with some kind of eyedropper tool. You would have to rework the painting approch to individual layers per brush setting to be able to do that, which would be a performance problem most likely.

How about a different approach to the problem that the eyedropper suggestions aims at solving...

The ability to create composite brushes.

Multiple layers, each layer has thje usual paint brush properties, like texture, radius, opacity, softness, etc. and additionally a paint priority (like the brush layers)

So, for example, you could with a single brush stroke paint a 100% opacity, max softness dirt bed and then paint a smaller road texture on top of it and again paint some 30% dirt on top of the road, all with a single stroke of a brush.

This would not touch the architecture of the painting layer and yet greatly simplify complex texturing tasks.

As a bonus you could save those composite brush presets per map and globally. :)

This would be hugely helpful when I'm modifying a map or editing a map I've built a while ago.