Allow customized expiry time for cache entry

We are building an aggregated services and using Akka Http Server to expose service endpoints and Akka Http Client to call underlying services. These underlying services require JWT based authentication. To maintain the token, we were thinking of using Akka Http Caching, but it seems it does not support dynamic expiry for cache entry which is required for JWT token.

Caffeine has provided a support for that. It would be a good idea to integrate it with Akka Http Caching. Thoughts?