Does VoIPo do ENUM lookup, keep VoIP calls off PSTN?

I have family that use VoIPo. I use VoIP also, though a different provider. It would be nice if calls between us could remain on the internet for a number of reasons. I am registered with e164.org and ENUMplus and have confirmed that I can make and receive SIP calls on my end.

If my relatives were to call my PSTN number, registered with e164.org, would VoIPo servers be smart enough to realize the call could be completed pure SIP? Or would it route onto PSTN?

We do some ENUM lookups but it's through a commercial peering registry. We don't use the E164 registry.