Paypal Modification

I must admit that my customers really like braintree addon Dropin UI paypal feature from Simtechdev

Originally PayPal website payments would take you out of website and this may or may not results in some not complete transactions.

PayPal express checkout is little better it takes customer login within view cart page, but problem is some customers bypass cart page and I do not see point in forcing them making extra step to checkout.

PayPal express checkout in checkout steps works pretty same as standard paypal, is trigered only on action of submit order, what results in order itself or incomplete order.

What I want to atchieve is uppon radio button click of paypal express checkout, paypal customer details iframe window would popup as in view cart page would, then if person is logged in to paypal, submit order would be very last action for order to be created.

How can this be done?

While braintree is fine, having funds directly in paypal allow instant use of funds, while braintree fund releases still take couple days..