> A Scheduler.Worker is already single-threaded and work is never scheduled onto a Scheduler but a Scheduler.Worker.

But operators take a Scheduler, not a Scheduler.Worker. If I want channel everything to a single dedicated thread, there is no other option but to implement a custom Scheduler. 

> This would imply no one is using Scheduler.computation(), the system default that uses all cores.

Exactly. For example, if one has to consider other things running on the same box and is only given 2 cores from 8 for computation purposes.

Anyway, If there is no demand for these bounded schedulers besides me, we can drop the related changes.