Normalization: Should I do this in 2NF or 3NF?
If's a design choice, and you have to consider the trade-off:

If you use 2NF, there will be some duplication, which can potentially be detrimental to integrity - you can change a value in one place and not in the other.

So, if you decide to go with 2NF, you have to be more careful about integrity.

If you use 3NF, there will be no duplication. But you might end up with too many tables, and have hard time keeping track of them.