Thanks @Vitalikssssss, I am assuming I will need to add the SAML app on G Suite's side, but mostly I was just checking if there was any other option eg just going with Google as a scoail login and restricting the domain or similar.
We will set up the SAML app in G Suite and then work on figuring out the necessaries for Caspio, and I'll come back here and share our experience when it's done. Or abandoned :o)