Enable Renewal change made during subs period

If we have a plan on a fixed expired date and one of the parameters are changed during that period, does the change take effect to new subscribers only OR does it also apply to existing subscribers as well? For example, if we changed the Enable Renewal during the year from NO to YES would everyone be given the option to renew on the expiry date, or does it depend on what that setting was when they became members? Another example, if we changed the expiry date, does it apply to everyone already on that plan OR just new subscribers after the change has been made?

In case others have similar questions, let me answer from my own testing. It appears that changing the Enable Renewal config setting from No to Yes during a subscription period will enable it to ALL existing members (not just new members from the change). This makes sense. Note that you may also wish to set the period to allow renewals in each plan.
Changing an expiry date on a plan during a period however only applies to new members joining after that change. This also makes sense as it allows us to make this change to each plan on 1st October each year and open up next year's membership plans early for new members, effectively giving them a bonus period to the end of the current year, plus the full next year.
Tuan if any of the above is not correct, please comment.