Hello Marcel,
Even if this is the case, Scheduler is not designed to wait for inbound data, so we cannot be sure that you won't run in any trouble with this method at some point.
Best practice with your use case would probably be to use a different workflow for each channel. Each workflow starting with a scheduler, then retrieving the targeting data using for example a Read list activity, and triggering the delivery.
Using different workflows is also a general best practice as the simpler workflows are, the easier to fix it is in case of problem or error.
Let me know how it goes for you if you still decide to keep a single workflow, that could lead to a nice example to share with the community.
Florent.