I think with the “plugins setup ON/OFF styles” you can achieve that with the “Plugin Groups”. I’m not sure what exactly you mean, but with the Plugin Groups you can group plugins together and just enable or disable that plugin group rather than every plugin individually.
But I also think I understand what you mean. You mean basically what the “Search Plugins” page does. You choose what plugins you want to load on search pages, then just save.
Where as for the categories you are suggesting a similar page where you can choose what plugins to load, but have that list of plugins affect the category pages? Or add a specific permalink to that plugin list that targets the category pages, archives, tags, etc.?
I think this sounds good, but I’m not sure how the categories differ from theme to theme and if a strategy of that in some sorts would work across the board. I’m not saying it wouldn’t just not sure, but assigning a permalink would cover that.
But more so, I don’t know if it would be worth the work when having a wildcard would be easier and more robust to use across all areas of the site. So, personally I would like to see a wildcard more than anything else, besides the updates already in the works.
Though for me I only use one theme and my theme has category pages that work just like regular pages which gives me the control I need. If you know how to work with php you can do the same for you theme. Let me know if you are interested.