Corey, I can’t agree with you more. I believe that private/members only website are a small percentage of the WIX total website, therefore our needs get very little attention. It unfortunately but I’m looking for an alternate provider as there has been no progress on this issue in almost a year.
Well J.D. it’s been 11 months and not a word on when WIX Editor X will be providing private / members only websiteas with the abilitiy to create a custom login page! I guess all we can do is continue to wait, I’ve tried everyway possible to get the attention of someone at WIX, to no avail! 
Still waiting…since launch…where they said it has all the same business solutions as Wix…except it doesn’t…
Corey I’ve sent two emails to hi@editorx.com over the last two months trying to get an update, but never got a response on either. I think the answer is “when pigs can fly”. Sorry bud I’ve tried everything but nothing has worked. I thought WIX provided much better customer support, guess not.
I can’t believe that 15 months after the start of this conversation and there is still no capability in EditorX to create a custom login page for private websites! 
It’s available on studio (via lightbox), which is replacing editor x.
However I wish they would let us create custom login/signup pages and not just lightboxes. I built a SaaS product and it just doesn’t seem like they care too much about SaaS products unfortunately.