After adding the Z-Wave devices to Home Assistant following the instructions in this thread, 4 devices are added to HA:

1. The Z-Wave device itself
2. A "light"
3. A switch
4. A sensor for the battery

The switch is used to control the iblind tilt from closed (0% brightness) to open (50% brightness of the "light" - value of 127).  However due to the modifications for the xml file noted, status cannot be checked.  Therefore the brightness level is never known.  And consequently the only way to know the state of the device (open or closed) is to query the state of the switch.

I personally have 3 shades side-by-side and notice some strange behavior with the switches.  When triggering all 3 switches at the same time, the units will always run sequentially.  The iblind will move fully to the specified state before the next iblind activates.  This makes opening and closing all 3 blinds unnecessarily slow.

As a workaround, I've grouped the light devices for the iblinds, and send a turn_on, with a brightness of 127.  This will allow the devices to trigger in parallel. In practice, they are not synchronized based on varying Z-wave latency to each device.  Nonetheless, it's still faster.  As noted, HA won't know the blinds are now open since the state is not queryable.  To work around that issue, I've also grouped the iblind switches.  After I open or close the blinds using the light group, I then turn on/off the switch group so the state matches.  This takes a few seconds per blind to reflect the state change, but doesn't actually move the blind -- it also very likely consumes battery with the additional Z-wave messages.

It's an ugly hack, but it works...

Not sure why the switch device locks up the Z-Wave network exclusively (for any Z-Wave device on the network, not just the blinds) - maybe some kind of synchronous polling until the motor stops moving and confirms it state?  Is there a better way to get the iblinds to move in parallel asynchronously other than my workaround?  Is this issue fixable at a lower level?