Hello @TCAM,
I´m afraid EzVPN only work with IKEv1 since if you want to use IKEv2 it will change from EzVPN to FlexVPN. this is what Cisco says about it:
"FlexVPN is based on the IKEv2 protocol, which is the next-generation key management protocol based on RFC 4306, and an enhancement of the IKEv1 protocol. FlexVPN is not backward-compatible with technologies that support only IKEv1 (for example, EzVPN). This is one of the key considerations when you migrate from EzVPN to FlexVPN."
Also, FlexVPN is only supported on Routers so far so as I said before that´s is not supported. Link for reference: https://www.cisco.com/c/en/us/support/docs/security/flexvpn/115013-flexvpn-migration-00.html
HTH
Gio
