Not sure where you get "radio aliases" (I gotta look that up), but SDS displays are showing UID's of 8410xxx.
Apparently, Harris radios broadcast their actual radio name or alias with each call / command, and the tool I use (SDR Trunk) is able to decode that in the packet data sent in the control channel. This makes it easier to help decipher talkgroups and who they belong to, as well as determining radio ID ranges.
Screenshot for example - the "From" column shows what's actually sent with the data in the control channel stream. Sometimes the labels are NOT correct due to issues decoding, computer performance, or in the odd instance when a city installed a radio meant for one thing in another vehicle (American Fork Fire's radio in their Medic Ambulance 51 comes up as "CHIEF-51-M" as an example). So you do still have to still do the good ol' detective work of listening to confirm - this just helps the process.
And to your point about UTA...yes, RIDs in the 0841xxxx range are mobiles and portables for field units.
In this case, you can actually see on the third line down showing the RID of 08410179,54A-NIELSON-P (you can ignore the 92527.00A part...I forget what this specifically means, but it's something to do with the system in general). So you get the RID, and the label / name / alias / whatever the "official" vernacular is called of the radio. Sometimes they have the agency ID in there, sometimes it's just a string of numbers like Highway Patrol.