And even if you use less SA and chitosan, it still remains a bad choice because the main effect of chitosan on stimulating plant immunity is mediated via jasmonic acid: SA and JA are in most regards mutually antagonistic. Although, chitosan is compatible with both 'mediators', it's not recommendable to externally add one UNLESS you have a specific pest where you know the main signalling/resistance pathway. I think that most of the commonly encountered pests in cannabis growing (I can only guess without a poll

) are mediated by JA or first SA than JA. Adding SA to chitosan will hamper any JA mediated response.
And finally, the effects of JA on plant immunity coincide with several beneficial effects for tokers (like resin production and control of DELLA proteins) whereas SA causes unwanted effects in the eye of a grower (like stomata closure).