Yes, we need to change this, but I think one has to change the background process and/or nothing to run behavior. In the VW VM the VM disables the heartbeat and enters some blocking call when there's nothing to do. Squeak runs the background process which calls a primitive that sleeps for a short time. The former is much better. If a delay is active as the VM does to sleep it schedules a wakeup event or supplies a timeout so that it blocks until input is available or the next delay.
We could still keep the background process and do something similar to VW, disabling the heartbeat until after the relinquish, and factoring the delay into the relinquish timeout.
Also the heartbeat already has facilities to change its frequency, so one could modify things to slow down the heartbeat, again ensuring that it ticks before the next delay expiry.
What approach (not necessarily from the above) appeals to you John?
best
Eliot