Solving that is all of an $8 leather cuff from Amazon and 2 short cuts (from a $200 knife).
Guys with larger wrists, there's not much chance of this coming off. You can also always buy a strip of leather yourself and a few grommet/snaps and make one.
Hey, that thing cuts like butter and is 9 inches of OTF beauty!
As for the mod, this of course renders the heartrate sensor useless, but it looks much better anyway