This can be difficult to answer. If changes are applied in files that only install/configure in the ISO, then you will need to manually port the changes.
As an FYI, we don’t plan at all to track the changes from now till the release and provide a procedure to manually execute. We track all changes since the start of this project and will provide a global migration procedure. You would have to find where your install stopped updating in there, which is not convenient.
But if the changes are system-wide and take effect without copying or editing something, then it will update without you porting the changes.
No one can answer that question cuz we don’t know when, where and what would be changed until the release.
If you plan on installing from the ISO anyway, I would definitely say wait.