Not related to this specific watch, but looking to replace my Garmin Venu (well, just wanting a new toy actually), I ended up with the Huawei Watch Fit 4 Pro.
It doesn't have ANT+ but it has HR broadcasting via BLE, and I was able to successfully pair it both with my iGpsport BCS300 computer bike and the gym treadmills (Technogym).
I'm not sure how many watches do this, it's never stated in spec sheets and reviews but it was something I was really interested in having - I don't feel "pro" enough to justify wearing a chest or arm HR band.