BigIP APM VPN Client Problem on Windows

I'm testing both the "BigIP Edge Client on Windows", and the "Browser-based VPN with Chrome or Firefox" clients (https://support.f5.com/csp/article/K98269316) connecting to an external SAML IDP. The IDP uses a newer javascript library that does not support IE.  

Since the IDP does not support IE, I see script errors during authentication. I'd like to be able to use the BigIP Edge Client for Windows but can't see any way to resolve the script errors since the Edge Client on windows renders the authentication pages with IE.  

If I use the "Browser-based VPN with Chrome or Firefox" client, then the authentication occurs in Chrome or Firefox, so no script error occurs. But I have a different issue in that both browsers allow the saving and autofilling of credentials. When the BigIP Edge Client for Windows is used, I can prevent the saving of credentials.  

So my dilemma is: is there a way to either with BigIP Edge Client for Windows render authentication with a newer browser (Edge), or with the "Browser-based VPN with Chrome or Firefox" client prevent the saving of credentials?  

Or perhaps there is another alternative I'm not considering? I do not have the option of changing the functionality of the IDP, nor the option to deploy group policies.