Custom BroadcastChannel provider?

We have recently wrote our custom PersistentStream provider (https://github.com/Surveily/Orleans.Streaming.Grains) which does a great job but is [not comparable](https://github.com/Surveily/Orleans.Streaming.Grains/blob/main/BENCHMARK.md) in performance to BroadcastChannels. Would it be feasible to write a custom BroadcastChannel in an attempt to achieve a similar performance level but with a persistance layer attached to it?

@ReubenBond @benjaminpetit @sergeybykov