Tacx route vs garmin watch indoor activity due to heart rate data

Hello, I tried to run virtual ride on my garmin watch connected to Tacx Vortex trainer. Except the speed, the values were same both on watch and in tacx app. The reason for speed diff is explained here:


Anyway, after finishing both virtual ride and tacx ride, its actually twice in Garmin connect app. I would expect this to be synced somehow but ok.

As I dont have heart rate monitor and without this you dont have such data in tacx run, the only way how to not have one workout twice and have BPM data and therefore training effect is to pair your watch with trainer and during each workout share your heart rate (broadcast mode), which is then displayed in tacx training. 

Does that make sense, is it commonly used?

Thank you for the information