I stand by what I said in the other thread. Save your money and keep it simple, bike to chase radio is not worth the cost and complexity. Your pits are all done between special stages there is little to be gained by talking to a racer 2 or 3 min before he gets to the pit. Also, you will find radios will add to frustration when they don't work out as expected.
"I couldn't wait for success, so I went ahead without it."