SAML : authentication with one IDP and two SP

Hello everybody,
I haven’t found my question/arch in the forum.

Nextcloud 17 with SAML is installed and configured on two frontends (SP initiated).
The two frontends are behind a VIP.
The VIP has got session affinity parameter.
The SPID is the same on each server but metadatas “AssertionConsumerServiceURL” and “saml:Issuer” are different because the server’s name appears.

I wonder if it is possible to configure the same values, for example by using the VIP’s name ?
Or what another solution SAML with cluster Nextcloud ?

Thank’s a lot