Download permission

We’ve seen Advanced Download Permissions was list in roadmap which is coming soon. And is there any progress or discussion on it? because we have implemented a simple permissions control of download by ourself to limit who can download a specific question, Sincerely looking forward for the official implementation.

When something is on the "Coming soon" column, then it normally means the next upcoming major release. Sometimes it might get pushed one major release.
It will likely only be available in the Pro/Enterprise edition, but follow this issue:

And just for reference, so everyone can follow along at home: