Let’s talk about the layout between mobile and desktop though (so let’s ignore the plugin for now).
I’m not sure if there is a mis-understanding here?
Basically, you want to add a specific layout feature to only a specified device type and only in a specific Category, is that correct?
Bear in mind that the Category setting will affect both mobile and desktop, it’s a global setting. There’s presently no way to say “apply this only to this category and only on mobile”. I think that might be where some confusion has come.
One workaround you may not have discovered yet is to clear the individual Category settings (as needed), and use this instead:
Which will then set all Categories to follow the Discovery list settings.
The logic is “is this feature for this type of Discovery List & device, or is this feature declared for this Category or is “set Category Defaults” set (in which case I’ll follow the Discovery List settings)?”
Please confirm if that makes sense to you.
If that’s no help, I think the “simplest” way of dealing with that would be to introduce another Category setting for each class of feature so we would have one each for desktop & one for mobile?
The downside of that is it represents yet another set of settings (four more) and this system is already very complex to set up in a bespoke way, with a very long set of settings already (as you’ve proven to some extent).
You could argue that you’d then do the same for Tag, so that’s another 4 settings! A total of 8 more settings (and all the associated increase in logic!).
I think you maybe the only person who’s found this a limitation?
That said if you wish to carry out or fund all the associated work, PR accepted.