Does anyone, as a standard, recommend installation of a high water alarm to back-up the pump or discharge lines associated with the sump pit?
I don’t put it in my report. But during the inspection I do explain to the client what they are, how they work and why I have one in my house.
I recommend battery back up sump pumps to paranoid clients. You’re not gonna hear a high water alarm if you’re not home.
Only if the area has a water problem and then verbally to clients that ask or seem to be worried.
Agreed, for people living out of town. After the big wind storm knocks out power comes the big rain to flood the basement. 
The Sewage Ejector pump gets the alarm, and don’tcha hate it when they call it a sump pump?
John Kogel
www.allsafehome.ca
What do you do if the alarm goes off?
I dont put it in my report either but it can be recommended if the situation is apparent. By the way I am a licensed plumber and there is a difference in a sewage injector pump and a sump pump. He was correct in calling it a sump pump. 
I recommend the high water alarm, a battery back-up system with warning alarm, and if in a municipally supplied area, a water driven injection pump with it’s “on” set higher than the sump pump.
But you can I use to install alarms beneath computer room raised floors that will dial a phone # 24/7 if one wants to pay the money.