Anyone using ThinOS with Citrix Cloud and Okta authentication?

We have a number of Wyse terminals, all running ThinOS 9.1 (of various versions).   We currently use them with an on-prem Storefront solution for logging in and presenting desktops, but I would quite like to move away from these on-prem solutions and take advantage of the Cloud Gateway solution which comes as part of our Citrix Cloud service.  This is essentially a Citrix -managed Netscaler device in the cloud.

In an ideal world I would configure the Cloud Gateway to use Okta (our MFA provider) and set up a FAS servers to handle SSO, but apparently that also changes the login experience to a webpage.  From past experience with ThinOS, I have found this to not work very well, as if/when the webpage times out the terminal goes back to the standard login box, which then doesn't work.  I am nervous of spending time and money setting up such a system, which would work well with the laptops, only to find it ruins the experience for our remaining Wyse terminals.

Does anyone use ThinOS with non-traditional authentication methods from Citrix Cloud, and if so, how do you find it works?