If I set up a subscription for 2 bags of Huel to be sent out on a 4-week basis, but then I need to order before those 4 weeks are up, can I manually place an order of my subscription and still get the 10% discount?
Or is it just on orders automatically generated by the subscription?
You could just cancel the subscription and create another one, which will cause an order to trigger immediately (the first order of the new subscription), and you should get the 10% discount from that.
Basically it doesn’t make sense to place a one-off order for anything which can be subscribed to, instead just subscribe it and cancel later on. You can think of the subscription price as the “real” price, and the one-off price as having a (11+(1/9))% surcharge built-in for the convenience of not having to go back and click on a “Cancel” button.