We recently had a pep talk from an aluminum wire rep, and she asserted that aluminum needed the paste no more than copper wire.
Yet, I am old enough to remember when every failure of an aluminum wire install was blamed, by the wire makers. on the lack of, or improper application of, the paste.
I also note that crimp lugs generally come with some sort of paste in them already.
Since you mention service conductors, what does the local PoCo say?
Trade practice is not really enforceable as law ... there is some room for 'neat and workmanlike' calls ... but I consider using the paste necessary. If nothing else, it removes one future cause for argument. I don't get paid to argue.