Thanks, Gunnar.
Not fully understand your answer, maybe my english downs this night. I'll back to this in the morning.
But this is what I have in mind now:
* **unique** - how about to play with reflexion a bit and replace `metadataKey` with desired value after test start? I think fix that issue is out of this PR
* Clear metadata -  `redisTemplate.delete(metadataKey)`
* Start an adapter, as it is `auto-startup="false"`
* And make several `receive` from `inbound_twitter` channel
* `stop` adapter, e.g. from `interceptor` with `CountDownLatch` on `<poller>`, or with custom `trigger`, who allows only several polls.
* and here - `destroy` and `refresh` AC, and repeat `start` and `receive`, but with new messages as expected result for asserts.
* **removing from MDS** - let me guess - `MetadataStore.remove(String key)`?

Think it's enough for now. If I'll have time tomorrow, I'll show what I mean.
And you'll point me out where I don't understand `MDS` concepts
Thanks