Got some of the answers:
"It may be possible to turn the shaft encoder and get
pulses into my chip that are faster than it can respond to. It won't look for a new pulse until
the previous cmd has finished sending, which might be 100-200 mSec depending on the
remote and how long a sequence you record. In that case, you would not get a consistent
mapping between volume position and volume setting. If you turn the volume slowly, you will
send on every pulse. If you turn it faster, you will miss pulses. Not sure if that will be a
problem or not."
A) We can't use the Keypad mode. Sequence is repeated as long as key is held.
B) You have to record as short of a learned command as possible. e.g. minimal keypress time on the remote.
Waiting for another answer.
So far, not ideal. Ideal would be something far more complicated. Ability to send just the command and a buffering of counts that would. e.g. If you turned it 5 clicks, you get 5 pulses. If you turned it 10 clocks and back 5, you would get 5 pulses. Pulses would commence immediately and then add or subtract on the fly. Not possible without a microprocessor solution and knowing the actual IR code.
So, we will see how your total number of volume presses figures into things. i.e. would 1 press per 1/4 turn be too many or two few. (16-20) presses per turn might be too many.
Need another piece of info from you. What's the diameter of the knob and how far can you turn it with one grip of the finger? I'd guess between 1/4 and 3/4 of a turn? Next step would be to estimate the time it takes to turn it. e.g. Turn it back and forth 5x and divide by 10. So, how far, and time would also help a bit. I can directly read 0.1s on my watch as a stop watch. Could go to 0.01s if someone else could push the button.
Thinking out loud:
Sparkfun has an illuminated encoder
https://www.sparkfun.com/products/10596 with 24 pos per revolution. They also have a clear knob and a PCB to mount the thing.
Suppose, we used the Illumination to indicate the command is sending? Again, dunno if the LED lights on the IRMIMIC when the IR command is sent as well. Gotta read and then ask. If not, I can create one.