I've mentioned a few times that its a bummer that the radios don't do this since 1200 baud is reserved for slow speed data.
After further research, the IC-92AD HT that I have been considering does do it. The messages have to be preset as a sort of quick text. It will store 6 messages of up to 20 characters each, which can be selected to be sent.
The ID-800 mobile works similarly. It will store 6 messages of up to 20 characters each, which can be selected to be sent each time you key the radio. When received, the message will (SLOWLY!) scroll across the display on the ID-800.
Editing these messages is a royal pain, because (of course) the radios have no keyboard.
The IC-92AD also has a kind of cool built-in voice recorder function.
The built-in voice recorder records an incoming (directed to your callsign) call for up to 30-seconds (approx.), (or 15 sec. × 2 tracks, 10 sec. × 3 tracks). For automated outgoing calls, you can pre-record up to 10 seconds of your callsign and/or CQ message in the IC-92ADs voice memory.
This functions of the callsign squelch. Out side of the DVR mode, you can set the call sign squelch function to only open the squelch only when your callsign is received.
There is also a break-in function built into this that allows a user to break into a conversation, where 2 stations are using Call Sign Squelch. The breaking station should enter the call sign of one of the stations they wish to communicate with. When you call the desired station, only the selected station will hear the call. With the break-in communication function enabled, both stations will be able to hear the call.
D-STAR also has "EMR" mode, (Emergency" mode), that was the engineer's obvious intention -- it opens all monitoring radios and even turns most models volume up to 50% if they were turned down, in order to get your call heard.