Update multiple image availabilities at once

[initBasti]

The plentymarkets API only present the POST route /rest/items/{item_id}/images/{image_id}/availabilities to update a single image availability. Using this to update multiple image availabilities is highly inefficient, as the request limit is reached quickly + it's very slow.
I currently experiment with the PUT route /rest/items/{item_id}/images/{image_id}, which offers the possibility to update multiple availabilities at once, but it has a drawback, namely, it requires the user to provide all existing availabilities as well, because every option that is not mentioned is unset.
This means, that we would have to make a GET request for the item first and then use that data in concatenation with the new data as a request body for the PUT request.

The question is:
Should we check the length of the new data and then split internally between those 2 routes.

Or should we provide two public methods:
plenty_api_set_image_availability (for a single availibility)
plenty_api_set_multiple_image_availabilities (for multiple availabilities)