If you have visiting guests using WiFi cards not manufactured for your country, advertising the 11h beacons may allow them to use the correct DFS channels for your country. They won't use any illegal DFS channels because your APs don't, but they may have trouble with specific APs if the 11h info is not advertised.
We run with it on, but we currently have not yet turned on channel change notifications -- among the standards waiting in the wings for old clients to age out, the channel change notifications are probably the very next thing we will try to turn on, then 11k.
You can view which channels your APs are on with a "show ap active" on the controllers.
To see Radar events, grep the controller syslogs for "Radar".
As to whether your setup is adhering to DFS requirements, it's on the vendor to provide proof of that during device certification; you just need to select the right country and make sure all outdoor APs are provisioned as outdoor, unless there are additional local restrictions due to your location.
EDIT: slipped my mind cause I don't use them: also tell the system the correct gains of any external antennas.