Read carefully:
Open World Loot is a brilliant mod, not because of what it does, but because of how it does it. It provides a framework so tidy that making patches becomes a (bit tedious) breeze. All leveled lists have been compartimentalized and linked back to some primal leveled lists that build the core of the mod (those starting with OWL_whatever). Thus, just by adding or removing items from those lists, you will change everything else, that only depends on these aforementioned lists.

Problem: All the lists that are based on 'OWL_whatever' lists are meant to stay that way, and if some other mod loads after them, said lists will be overwritten. And if you dare make a bashed/smashed patch, you end up in a mildly infuriating compatibility hell. Nothing world ending; it would mean that OWL wouldn't work as intended, meaning it wouldn't work at all, since OWL isn't designed for anything else. The most elegant solution here would be making a synthesis patcher, so that every list that OWL modifies that is meant to stay a certain way, actually stays that way. This has already been done, but I couldn't make it work properly (if you could, outstanding for you) since synthesis ended up mixing my lists with OWL's (and they should be left only as OWL intended).

My solution: This problem immediately made me think that, if only the 'OWL_whatever' lists were needed, all the other ones (save some exceptions) could be dropped out of the mod and into another mod, that would be loaded at the end of your load order, fixing every issue, known and unknown.

So hereby I present you Open World Loot LeveledLists Override.esp. Instructions on how to use it:

• Download with a mod manager (and mod manager only).
• Make every bashed/smashed/synthesis patch that you need. In these patches, never include: my mod, Randomised Special Loot (in case you use it), or patches for Randomised Special Loot.
• Now, put Open World Loot LeveledLists Override.esp at the end of your load order, whatever it is, and after all your smashed/bashed/synthesis patches. I would recommend creating custom rules for LOOT's sorting.
• If you use Randomised Special Loot from OWL's page, load it after my mod (thanks Ghastly for reminding me about that esp).
• Profit.
  

ESL-flagged for your convenience.