Hey Vito,

Thanks for the question. The short answer is yes, the URL would be unique for every FI. The longer answer is that I think it doesn't much matter. My expectation of what that IdP Sign Sign-On URL is used for is when the end user shows up at the Service Provider (your app in this case) and is not current signed in, your app would use it to redirect the end user to the IdP Sign-On URL. This is not a likely scenario with our OLB SSOs so I would think that setting could be left blank or filled with some default value and not have any negative impact.