When looking at Paypal's page explaining their services, there is a checkmark that implies that 'Subscriptions with fixed amount' can be used with Adaptive Payments.
However, I've read similar questions which state that you have to use preapprovals alongside adaptive payments to 'fake' subscriptions.
I'm looking to specifically use parallel payments, so that the customer is charged $100, my account gets $80 and a third-party account gets $20 (for example). This works fine for individual purchases, but that checkmark leads me to think I can do the same for subscriptions, where the customer is charged $50/m, and each month, I receive $40 and the third-party receives $10 (etc).
I'm wary of using preapprovals for this because I do not need to modify the amounts or splits of fees after the customer agrees to it, and would prefer not to be responsible for each month issuing those charges manually. If I could simply use the standard Express Checkout way of setting things up, but dictate that a third-party account gets paid as well, I would be completely set. Looking at questions like this which say EC can be used with adaptive payments, that seems to break it down to the customer as two distinct products, which in my example is not correct as it's one individual product with the same name and details, just a percentage of it's cost going elsewhere and doesn't have any info about recurring payments.
So my question is - what options do I have for this and is there anything that could be done?
This doesn't seem possible, so I'm marking this as the answer. I am using preapprovals instead for subscriptions.