Is your feature request related to a problem? If so, please describe.
I have many items in my bag that stays there permanently, such as bandages, consumables, hearthstone, equipment and so fourth. I would like to arrange these once, and have them stay that way without being affected by sort / cleanup.

Sort / cleanup is something I mainly use on newly attained items.

Describe the solution you'd like.
As a player
I would like to select one or more bags to be ignored when using sorting / cleanup
So that I can have a set of (permanent) items in a fixed location

Any additional context?
Similar functionality is available in the addon SortBags by running the following command:
/run SetBagSlotFlag(bagId, LE_BAG_FILTER_FLAG_IGNORE_CLEANUP, Boolean) -- Set bag ignore status - bagId in (1, 2, 3, 4), doesn't work for main bag

Adding to this, as I literally just came here to make a feature request to be able to disable the cleanup button entirely, and saw this feature request from a few days ago along a similar vein.

I personally have all of my bags and bank sorted exactly how I want them, but if I accidentally left click the "Deposit all reagents" button instead of right clicking it, it absolutely destroys all of my organization and I have to spend 30+ minutes fixing it all manually.

It got so bad a few years ago, driving me to the point of absolute frustration, that I just went into the code with Notepad++, located the lines about the sort button, and just deleted the entire line of code for sorting bags and replaced it with DepositReagentBank(). Then every single time that the addon has been updated since, I've just been doing the same thing, but because I hardly know anything about coding I don't think it's proper syntax, and it just causes errors instead of actually doing anything (but at least it does stop the button from "sorting" my bags).

I finally decided today after seeing a new update that I would come and make a formal suggestion to add an option to the addon to disable the sort button entirely, (while retaining the deposit functionality), when I saw this suggestion, so figured I'd just add to it instead with a request of the option to ignore all bags.

Still a very much wanted feature.