Chris,
Yes, you right I would be able to use coupon/discount codes generated by S loyalty app or just created manually only in original Shopify checkout, so if customers purchase non recurring product with mixed recurring option chosen within the Recurring Orders app, they'd also be able to use coupon codes. Alternatively, there is a "Coupon codes" section in Recurring Orders app, where you can manually add these coupon codes generated by S loyalty app.
