The 436 has a headphone jack. People have been able to deliver the screen data over a serial connection via the USB port, so alpha tagging would certainly be possible too (though IIRC the display/command set is slightly different from the HP1, so programs would have to be updated to take advantage of it). The command set has not been officially published for the x36, so programmers might be waiting for that before they build in support for those radios.
I successfully ran a special events feed a couple of weekends ago, complete with alpha tags, off an HP1, and despite what I said above, the 436 is close enough to the HP1 that it should be possible.