Is it possible to create a JOSM style that shows items from non-active layers?

When dividing up areas for tracing I often have a background layer to mark the area I’m working on. Sometimes this is generated by a task manager and sometime just created by me.

Is it possible to create a map style for these layers so that it will not be greyed out if I mark a way with a specific “junk” tag? e.g. asdf=asdf or no-upload=junk

At the moment I tag them with something like natural=cliff or import an untagged copy of them into the edit layer so that they can be highlighted by the validator, but I don’t like either of these solutions as the first can be overlooked with busy background imagery and the second can be accidentally uploaded. I would probably try to add the tag I use to the validator as an error too so I can’t accidentally upload it if I mistakenly merge layers.

Edit: I realise I can convert them to gpx but this isn’t a great option as I often want to change the size of the divisions based on housing density and once it’s gpx it stops being editable.

The Josm display settings may help but you then have the inconvenience of undoing the change when not needed, but you may find a good compromise that suits all use.
See this help site query…