Just ran to bike to test my range. New-ish batteries, no further than the pillion. After that, no detect.
Another hack is that 2 people work together, one near target RF relay. The other person is next to bike with the receiving end of the RF relay. Think of "extension cord". The vehicle knows nothing other than the key fob is there. Bad Guy starts vehicle, and at that point, as long as they don't turn off, they're good!