Earlier quoted context omitted.
The Core Time 2 mentions heart-rate monitoring. Have you considered also adding an oximeter? The comparison chart, under "sensors", doesn't mention the compass under the Core Time 2; does the Core Time 2 drop the compass? A 3D magnetometer seems like a useful sensor for orientation purposes. Is there a light sensor, to allow automatically disabling the backlight when there's enough ambient light and enabling it when…
You cannot put oximetry in a watch without getting sued by Masimo. Just ask Apple.
https://www.tomsguide.com/wellness/smartwatches/apple-watch-...
> This week, the US Court of Appeals for the Federal Circuit upheld the previous verdict of the Patent Trial and Appeal Board that concluded all three of AliveCor’s patents were unpatentable. This is generally the outcome when courts conclude that patents are either obvious or too generic to enforce.
The case over the oximeter functionality is still ongoing, but with luck it'll go the same way.