Is it possible to connect a banner with an empty adsense block?

Question

JavaScript

Hello! There are 2 tags in the subject of the question, because the first part of the question relates to javascript (or jquery) and the second, directly to the adsense itself (rules)?
In adsense, the "Ad Impression Percentage" feature is working again. I have a percentage of 66% set in my settings. in 66% of cases, ads are shown, and in 34% these are just wasted impressions, otherwise the income would be a third higher (I think so... plz correct me if I'm wrong. Maybe these are really empty and hopeless impressions). Accordingly, I would like to monetize these 34%.
Adsense itself does not provide an opportunity to show some other block (another affiliate program) in its place, in the absence of advertising, but simply shows an empty place. What looks ugly ... Yes, and in vain ...
Therefore, the questions are:
1. How, after loading the page, to determine on the javascript side whether the block is empty, or ads are shown there (plus .... given that the adsense code is executed asynchronously, on which event should the code that determines this be run?)?
2. Can this be used in terms of rules or some other restrictions of adsense itself? (searched, nothing specific)