GST rate on feed Supplement to be exported under IGST - Goods and Services Tax - GST

Dear team we are exporters of veterinary products and as of 8th oct, 2024 Rule 96 (10) was removed, which was restraining exporters to claim refund for IGST paid so we have now shifted to raising of invoices as exports under payment of IGST. we are required to charge Freight insurance as per the shipment and since we are not into freight business then tax rate applicable on principal supply shall be applicable on Freight Insurance while raising Tax invoice under GST (according to composite supply definition) my concern is we have certain products which are feed supplement and as per HSN code under GST which is 2309, tax rate on such invoice is Nil and consequently there is no the need of charging GST on Freight Insurance (if we go by composite supply defn). Only exchange rate should be taken into account while booking invoice in system ( kindly clarify. interpretaion from experts will be appreciated