MarketPress - global cart plus chained payment

I just read in a forum post the following (reference original post at https://premium.wpmudev.org/forums/topic/marketpress-help):

" I hope you guys are figuring out how to use chained payments with a global cart because that would be exceptional.

We are. In fact, it is possible already - but PayPal has limitations in their API for this scenario:
1. Global Shopping Cart (separate stores) = Max of 10 stores per order
2. Global Shopping Cart (separate stores) + Chained Payments = Max of 5 separate stores per order"

I need to set my site up like #2. However, when I enable Global shopping cart, the paypal chained payment section disappears. I really need help. I have submitted a number of questions via the forum and through this option and am not receiving any responses, despite the fact that I paid for the service and was told I would have support.