When you set a clip region, the number of rows involved come into play. And if you have two or more the top row to botton row come into play.
Here's that WF in the sim:
There can be actually 2 clip regions here. The seconds, which change every second, and the HR that changes but not as often, so I only use the second clip region when HR changes. So you can see the number of rows involved is far less that the screen height.
In the 1hz sample I posted, I'm pretty should I have comments in the code to try things with and without clip regions, but you do need them.
So in an analog face, the most rows are when the hands are at 6 and 12, and the least at 3 and 9. That's where the 30ms helps as at 3 and 9, updating the screen is much faster than 6 and 12.
Without clip regions you'll exceed the 30ms average all the time,
One thing about MIP is that the use ambient light, so in lower light environments, they are harder to read, but are great in bright sunlight,
Also, colors don't look the same as you'll see in the sim. For example, with MIP and red text on a black background is kind of hard to see.
I guess I need to see it in store, but I love the idea if I'm done with tweaking in theory it would be possible to constantly monitor my recoverytime, hr zone and stresslevel. However the hr zone will be a pain as it currently is showed by the color of the clock numbers.