My apprehension of adding niche data is because I worry about the limits of update time. Particularly on lower powered machines.
Now it may be based on no practical truth at all as I have never tested this - but logic dictates that there must be an upper limit.
Once added it would suck to have to remove it later.
Joint velocity command is available via HAL so there is an alternative.
You are the first I know who have asked or mentioned it.
I would reconsider given compelling reasons.
Chris