Is Arcane Recovery overflow wasted, or can I use the remaining slots on a later short rest?

Question

Is the Arcane Recovery feature something you can only use once per long rest to recover up to a number of slots, with the overflow wasted? (Similar to how healing magic works)

Or, alternatively, is this a "point" resource that can be drawn upon at each short rest, and simply refills on a long rest? (Similar to Sorcery Points)

You have learned to regain some of your magical energy by studying your Spellbook. Once per day when you finish a Short Rest, you can choose expended Spell Slots to recover. The Spell Slots can have a combined level that is equal to or less than half your wizard level (rounded up), and none of the slots can be 6th level or higher.

I think I know what answer will result, but figured there may be others with a similar question.

An example, a level 5 Wizard would have 3 slots of Arcane Recovery per day.

Scenario A, the Wizard is only missing one level 2 slot on her first short rest of the day. She uses Arcane Recovery to restore that slot. Later in the day she's used more slots and wants to recover one of her first level ones, since she's only used 2/3 of her Arcane Recovery slots. Can she do this?

Scenario B, the Wizard is missing three 1st level slots. She chooses to recover one first level slot now, but decides to wait until a later short rest to potentially recover a 2nd level slot. Can she do this?

Answer 1

She can use the feature once, and then must wait until the next day

Note that the feature states:

Once per day when you finish a Short Rest, you can choose expended Spell Slots to recover.

Everything after that is just a specification of the maximum level and number of slots you can regain, but not necessarily the levels of the slots that you actually regain. From this excerpt, it is clear that there is no pool. You use this feature once, and then can't use it again until the next day.

In your example, scenario A is not allowed. She already used the feature to get a slot back, and so can't use it again. Scenario B is not allowed either for the same reason. However, if the wizard spends a slot and finishes a short rest without using her recovery, then she has it available at the end of her next short rest.

Answer 2

The number is a limit on the previous sentence: how many expended slots you may choose right now. This doesn't carry over — once you've chosen the expended slots to recover, they recover and the limit has been satisfied and the ability is done.

The ability doesn't look backwards to increase that limit based on previous rests, or explicitly create a point resource, so there's no carry-over created.