Chain Payments: Unclear how a network of MarketPress shops can shop without a global cart?

MarketPress Network of shops using Pro3 theme floating cart, and chain payments.

Not sure how MP shopping cart (floating cart) works. I may have misunderstood its function for chain payments.

I deselect global shopping cart to use chain payments. (I cannot use global cart and parallel payments with chain payments still, correct?) I can no longer track my network shopping spree, and I lose track of what shop I shopped in!

Can you clarify for me how this will work for shoppers in a network?

As a shopper, I have to go in to the shop to see what items/subtotals I have in my floating cart. How do I keep track of what shop I visited, or what the grand total is? I could get lost fast!

I would like a global cart functioning in a network of shops with my shopping cart info in all the time, to track the shop and their items/subtotals for me, no matter where I am in the network. Then let me choose which shop/items to go ahead with at store checkout time.

I would like to add my payment and shipping data in once, and have that entered into each shops store-checkout table, then follow through with each one at a time to fulfil chain payment requirements.

(I received credentials for chain payments, but getting ready to test, I noticed there was an additional $35 monthly charge to process credit cards - is this correct?)

Thank you.