Efficient way redis set member update

Question

I have a redis set. This set can store 20 members maximum(added withSADD command). My problem is ; I need to update that members when needed. Members need that

Answer 1

Set members themselves are immutable - you can add new members or remove existing ones. That's it.

Given that a set is an unordered collection of unique members, consider the possible outcomes were set members theoretically modifiable when the new value for a member:

1. is identical to the old value - no change to the set
2. already exists in the set - equivalent to deleting that member
3. isn't 1 or 2 - equivalent to deleting the member and adding a new one