Configurable options setup fee
Setup fee for configurable options is calculated on invoice only if option is ordered with product at initial order.
If client order configurable option any time later setup free is not added to the invoice, just option price (if exist).
So, if you have some configurable option that is charged only once (setup fee) and recurring price is free, client can order this option for free, without paying any setup fee.
This needs to be fixed ASAP !
For example, we can sell backup space for vps/dedi. This can't be defined as product addon, but only as configurable options where client can select "None, 10GB, 100GB, 1TB, etc.".