It would appear when filling out a request for a BLUE Alert (pdf) and submitting it to the DPS[1], there are no fields present allowing the submitter to specify how large of an area/region should be included. This leads me to believe the TX DPS in Austin is at fault for setting the area to way, way larger than reasonably required.

The above "7 hours away" is not an exaggeration, this alert was upper NW TX and anyone who lives in Southern TX is 7+ hrs away driving really fast with the wind at your back and no traffic.

[1] https://www.dps.texas.gov/section/intelligence-counterterrorism/request-alert-activation