I found a solution by chance, gilded blackstone has the exact type of thing I needed, I just happened to learn that while trying to balance a crafting recipe for it.
for those that needed it, the solution is "table bonus" under conditions, and each entry under chances is that many levels of fortune, after the first one, and if you don't have all 4 entries to specify all 3 fortune levels, it just uses the highest level set.
