The easiest way is to increase the cache size on the endpoint, and use standard ‘prefetch’ statements. As long as the cache size isn’t exceeded, the download won’t be cleared.
We do have a separate cache called the utility cache that could be used. It is intended to store downloads that are used frequently (usually across different actions), so they don’t need to be downloaded repeatedly. Typically these are smaller files, but if the use case fits that intention, then it would be appropriate. Take a look at this post for details: https://forum.bigfix.com/t/utility-action-how-does-it-work/9637