I'll let you in on a little secret: The default watch face does not run on the main processor, but instead runs on a much lower power micro which doesn't have enough memory to run Connect IQ. It honestly doesn't have enough memory to hold the screen buffer; I work with some mad/crazy embedded hackers here at Garmin. All that for a second hand.
We face similar challenges to other smart watches when it comes to balancing functionality and power usage. I think all smart watches have been figuring out how to offer the customize-ability of custom watch faces without killing the battery for the use cases the devices is intended before. We're starting with a conservative approach, but it could evolve over time.
-Alpha Monkey
...So to get back to this thread, it got me thinking that maybe we could poll for the seconds only when say the power/ button was hit, then have a counter count them down for us, and then turn that field off again once a set time was up.
This would;
1. Let us save power by not refreshing every second.
2. When the user asks for seconds we can display them.
3.then after a set time it would again turn the seconds off.