I don’t know if this will work in your setup, but this struck me as the simplest possible solution:

MIDI Clock is not channel-specific, so it will work across all channels on your receiving devices.  Can you set your downstream  pedals, etc. to another MIDI Channel?  Any one, other than the H90’s Transmit Channel?

I keep a MIDI Solutions Event Processor Plus under the pedalboard for problems like this.  Invaluable to me, but I understand that not everyone would want the added expense & programming time.