With regular Mega or Tinys, you just make DDRx.y an output for an OCnx pin, and set the COMnxy bits for your specific output mode.
OC1A and OC0A seem to work like this on a Tiny85. But although I can see bits changing in the debug IO view, there is no output on OC1B.
The TIMER1_COMPB interrupt is generated and serviced normally.
The COM bits are normal.
The Fuses are set for "Internal 8MHz RC" so both PB3 and PB4(OC1B) pins are available to the outside world.
Help. I must have missed something in the "Alternate Function for PB4", but I can't see what.