Configurable expiry for dependency caches to support builds with different dependencies

The caching feature in Bitbucket Pipelines is rather inefficient. Would it be possible to implement the following?

1. After a successful build, update the cache.
2. Define a max TTL for the cache.

Reasoning for 1 is that at the moment any first build populates the cache and it stays effective for a week. All subsequent builds during that time window need to download dependencies over and over again. That's really inefficient.

Reasoning for 2 is that instead of forcing downloading the cache every week, why not define a time-to-live for the cache? If there are no builds running for a week, then delete the cache (if you need to free resources).

If a project is actively building day after day, do not require rebuilding the cache unless there is a good reason to do so.

I guess there is a little controversy between the interests of Atlassian and Bitbucket Pipelines users since Atlassian charges by the minute and users want builds to be as fast as possible. I'd rather pay a bit more for faster builds.