I am struggling to understand those 2 issues matter in bigger scheme of things.
Dive delay- how does it affect anything physiologically? Might be annoying to get your surface location incorrectly, but I suspect it is a design compromise as one can't get GPS signal reliably while bobbing in the water.
True North - Modern instruments point to TN, such as in aircrafts and consistency is required. Regardless, where you dive (Monterrey) magnetic declination is 10m over 100m swim in a straight line. Now which use case you can't address with TN compass?
Currently, Garmin is the only smart watch with dive capabilities. Comparing it to another dive computer in terms of complexity is not an apple to apple comparison,