F5 APM as IDP using Custom Page

See if this workable

On APM create access policy on VPE:
1) Create IdP SSO resource 
2) Bind this to SP connector 
3) Create new access policy and attach the IdP SSO resource created
4) Configure Access policy with 'External Logon Agent'  to capture the credentials
5) Use HTTP AAA agent to do form based authentication
6) Redirect to Landing page