If you need PS80 to solubilize a fragrance, then use it. But you've drawn a blanket conclusion that it's always needed and I disagree with that opinion. My experience shows PS80 is only sometimes needed.
Whether you're using EOs or FOs makes no difference ... just test and find out.
PS80 is functioning as a solubilizer, not an emulsifier, in LS, since the result is (or should be) a clear mixture. Not all emulsifiers can also be solubilizers. I've tried PS20 with poor results. There are other polysorbates that might work as well as PS80, but I haven't tried them to know.
The polysorbates can solubilize and they're easy to use since they're liquids. Those qualities are why they're used in this application. If you don't care about clarity and are willing to fiddle with a solid emulsifier, I suppose any emulsifier could do the job.
