What's the best version of Unity for importing? And what settings should I use to achieve the highest quality rendering? HDRP? Lighting?

You mention support for 2019.3, but that's not specific enough. I've noticed someone saying 2019.3.13(?) doesn't work, so which one should I use?

Is there a Unity setup that you, internally, use to test, and develop with? Is that available to your end users?

Thank you! I'm hoping to get this done in time for my client's bid to their client, and I need it to look as slick as possible.

Thank you!!