Most of the general federal services run P25 in the clear. However the law enforcement side will run full time encypted. Those who operate f/t encypted have the modes "strapped" to be secure all the time, and the operator cannot change it.
Those who run clear may have the option via a push button, but in the P25 mode, clear and encypted comms sound the same to the user so there really isn't a need to look down at the display to wonder if the radio is encypted or not.
Where I am, the NPS in two locations went P25 this year, secure equipped, but not used. In fact they don't evey have a KVL here. However, should the need arise or a letter from headquarters comes down, a KVL can be brought in and the radios can be loaded in 10 seconds.