Tiny spoilers ahead.
Compared to the first OVA which was more or less two side stories that aren't that important these two episodes are in my opinion a must-watch before starting season 3. Not only do they have a lot of character development and foreshadowing (especially the first episode), the second one introduces the Elite Ten in a much more well-paced way. The first episode takes a few scenes from the OVA and doesn't linger too much on it, this OVA goes in much more depth.
Story-wise, as I said, it's an essential watch in order to fully grasp some characters and motivations (especially Momo-senpai who sadly had 0 character development in the first cour of the third season while in the OVA there are a few scenes where she is more fleshed out).
In the other aspects like art, animation, sound, etc. it's consistent with the second season.
Also, in the second episode the best character in the whole series appears for the first time: Kobayashi Rindou, so that's a 10/10 by itself in my book.
