Ability to add other keys through adUnit (Prebid)

[tcassier-leparisien]

Expected Behavior

We'd like to give other keys than code and bids to adUnit object with prebid.
It is for monitoring purposes.

const adUnit = { code: 'adunit', pubstack: 'adunit_monitoring', bids: [] }

Actual Behavior

const adUnit = { code: 'adunit', bids: [] }

Additional Comments

Is it possible to implement something like this :

(source concerned : https://github.com/washingtonpost/ArcAds/blob/master/src/services/prebid.js)