Well, I did a little looking into this today while we are out on out maiden voyage.
As it turns out, on our model, knowing if the inverter is even ON is not easy to discover. Turning it off, must be done completely blind. You have to feel arou d and find the power button and then hold it for a couple of seconds. The inverter does have a readout, but it's totally worthless because you can't see it at all.
While I don't doubt the previous post about Keystone recommending that the inverter be trained off, they obviously weren't too serious about a statement like that if you have to be a contortionist to turn it on and off in our model.
At this point our plan is to leave it on all the time, and disconnect the batteries to turn it off. They definitely didn't make it easy to do in this model. One thing that would help with this inverter would be to get the remote switch for turning it on and off. May have to look into that...
Here is a picture of where it is located, and it's about two feet from the opening, so not close, and the end with the plug on it is the end with the power button and display panel, and that is 4" from the wall, so close there too: