I want to pay and in fact would really like to pay, but I won't until BT HRM works with the iPhone app again.

That is what would be the reason to pay if I could not use it with my HRM? Before they dropped HRM I paid for years, now I use the Wahoo app, but would much prefer to go back to Strava app so I could use Beacon and the other paid features. $5/mo is nothing, but is worthless if I can't use it.