SPT is next After pay ?, page-11

Exactly right.
The merchant has to go into a factoring agreement with the lender, it puts their entire receivables at risk. The lender takes a charge over their receivables which is a bit to ask of a merchant just to get paid upfront, oh and charged 4-5% for the privilege.

Its not to say it's not possible, it is possible to get merchant to agree, i guess, so the question is is there any risk to SPT?

Id say yes, the risk is the business model relies upon a) a lender willing to upfront these funds and b) a merchant willing to take a hit on their profit and have their receivables under threat, and c) the risk of fraud or cut cutting or disappearance by the customer.

Although a b and c doesn't directly affect SPT, it actually does hurt as its the 3 functions that underlies their own business model.

If the risk for the lender to get his money back is low, and the merchant gets paid upfront and their receivables are not ever hit, and the customer does the right thing, and the underlying banks don't simply do a deal with Visa and allow for interest free payments, then the model could work at volume.

here is the big question, does the SPT system actually pre authorise and put a hold over the credit card and authorised limit as it should? In other words does the system actually work 100%? To that i'm not 100% convinced, I still have this feeling there's a gap between the initial pre authorise and the next installment in 30 days where the pre authorised amount drops from the card.

You would hope this is not the case, but we had a client on here stating as such, and it states very clearly Visa only allow 7 day holds, so that perhaps needs to be proven/ clarified.