When looking for integrating OpenID I found how to construct the 3rd party initiated logon URI towards Spotfire which needs to include the issuer (iss) claim like below.
https://{spotfireserver}/spotfire/auth/oidc/v1/initiate?iss=https://login.microsoftonline.com/{tenantId}/v2.0
when using this link your current session is checked against the OpenID provider if I am correct allowing for a bit faster login (not having to click the button), or even skip the browser as the HTTP request can be done headless?
Do I understand you correctly that you have a Spotfire Server configured for multiple OpenID Connect providers and would want the Spotfire Analyst to preselect one of those?