I have to ask, does this mean that there is 100% no way to use the current custom fields, to be able to create a backend created subscription account for a client, for a certain plan and as one has negotiated a deal with them for the price - which is different to the frontend plans price, one can insert this agreed recurring fee in a custom field please?
To make it more clear, the custom fee field can still be used to calculate custom subscription fee for the subscription
We just don't have a separate line in the payment information section to display fee amount of each custom fee field. Fee from these custom fee fields will just be added to Total Payment Fee of the subscription (which users have to pay)
Hope it's clear to you. To understand it, maybe try to create a custom fee field and play with it to see how it works