I’m case anyone stumbles on this in the future, I was unable to find an app that serves the purpose I was looking for but after speaking to concept2 I did find

I’m case anyone stumbles on this in the future, I was unable to find an app that serves the purpose I was looking for but after speaking to concept2 I did find out it was possible to connect the PM5 to two devices simultaneously by using both the Bluetooth and the Ant+ capabilities of the PM5. There are two Ant+ to Bluetooth bridge devices on the market: the 4iiiive heart rate monitor and the NPE cable. You connect the PM5 to one of these over Ant+ then connect the bridge device to your iOS device over bluetooth. The PM5 Bluetooth channel is then free to connect to another device.