Currently it's not possible to completely disable our automatic affiliation of Amazon links if you are using affiliate parameters. We do have a recommendation to achieve similar results, but it's a bit of a workaround.

When you connect an affiliate ID to your Genius Link account, we don't perform any verification to confirm that it's a valid ID. So to avoid having your links affiliated to any real Associate account, you'll end up adding in a set of false / placeholder IDs.

Simply pick a random naming convention and add them in one at a time for each storefront: falseidUS-20, falseidCA-20, falseidFR-21, etc. 

Tracking IDs for each storefront have a different number affixed to the end, like -22. When adding your false IDs, use these numbers:
US, CA, MX & BR all use the -20 suffix
UK, FR, DE, IT, ES & IN use the -21 suffix
AU & JP use the -22 suffix
CN uses -23

If you don't ever want any of your links to be affiliated to real IDs, you can just remove all affiliate tracking IDs from your Default Group, using the Affiliate Page. 

If you intend to have some links using real affiliate parameters, and others using false affiliate parameters, you'll want to leverage our Groups & Overrides feature. The Affiliate page only allows one ID per storefront at a time, so if you want to use two different sets of IDs (one real, the other false), then you'll need to create a new Group and set override affiliate IDs for that group.