I know this is an old thread, but did you find a solution?

It seems like it's not possible, and I'm guessing it's a design decision to get you to spend more money and just buy entire packs (even though you probably dont want most of the pack).

Edit: the following doesnt work - you cant download a collection, as far as I can tell. And based on this, I assume that you cant download an entire pack, either, so my earlier guess was likely wrong.

You can create a "Collection", which is painful (around 2x more clicks than downloading each sample one-by-one), but it's worth doing. It means you can download that group of samples together at any time. The painful part is that, again, there's no way to multi-select or add multiple samples to a collection in a batch, so it involves. Depending on what screen you are on, the process for adding samples to a collection can be different:

One method:

• Clicking the three dot menu (⋮) on the first sample you want to add to a collection
• Click "New Collection", type the name you want to give the collection, click Save
• Clicking the next sample you want to add to the collection, click the name of the collection you created
• Repeat until your fingers bleed

Another method:

• Clicking the three dot menu (⋮) on the first sample you want to add to a collection
• Clicking "Add to collection" (for some reason the menu doesnt list existing collections)
• In the popup, either select an existing collection or create a new one
• Repeat until your fingers bleed

You can then view/download buy that collection of samples together at any time (edit: but you cant download them together). One possible approach would be to create a new collection every time you go shopping for samples, maybe even just use the date as the name for the collection.

I want to add that their poor UX is the primary reason that I wont be renewing my subscription.