OIN validation process

Hi,
I’m working on SCIM integration with OKTA.
I’m wondering if anyone has gone through the OIN registration/validation process lately and can talk about their experience.
I’m mostly wondering how much time the process takes so that I can set expectations with my team and customers.
Also (very important), is it possible to test the integration with our customer even before the OIN validation is complete ?

Thanks,
Ido