Not with SSO enabled.
If you’re going that route, I would have your users log into the fat client for classic and use the browser if they want the new UX.
Thanks - now to work on getting the fat client to all users without visiting each workstation. (I.E.) .Net Deploy, Certificate Install then Client Install - All Silent install via login script, GPO or Workspace One.
The Epicor client is pretty easy to deploy. There are several posts on here talking about it. It’s easy to upgrade and remove too. We’ve been on Epicor a few years now and I’ve never touched machines for deployments, upgrades, etc. All done remotely and automated. That’s one really nice thing about Epicor.