Is there any advantage to splitting up your tile maps into different .tres files?

Hi guys,

I'm working with sprite sheets and I have a typical background and midground layer for each scene and originally I was creating a new .tres file for each environment but because I have only a small amount of sprites per scene I combined them into all one .tres file and just reload the same .tres file on each layer.

Is there any downside to this? I can't find anything in the docs unless I missed it.