Download AssetBundles via Addressable

if you know the bundle path, you might as well just use UnityWebRequest. The addressable layer is meant to deal with the scenario where you want those details abstracted.

That being said, Addressables can download things up front. You could either do that by giving everything a label, or using the locator to get the .keys property (this second option is much more complex, and not recommended unless you want to get very familiar with our interfaces).

Alternatively you could use addressables for building and loading, but use direct UnityWebRequest to download the bundles in advance (using some other mechanism to gain the list of bundles). Addressables will check the bundle cache before downloading, so would utilize what you downloaded outside addressables.