Jumping on this topic little late, but what would be your recommendation for subscription billing, if we have to fulfill items and items are marked with Can be Fulfilled/Received?

My company makes a Built for NetSuite subscription billing product that accommodates use of fulfillable items (including using fulfillment as trigger for subscription activation). It's ARM compatible. We also sell/implement SuiteBilling. Each has strengths/weaknesses. Feel free to DM if you are interested.

You can create a Sales Order that combines both items as available for fulfilment & subscription items as non fulfill. The difference is the items will not be part of the renewal