Sorry to hear about your hail damage, but it sounds like you did get lucky with a near miss tornado.
As a retired Emergency Manager, I can only speak about local protocol for sounding sirens (and Indiana statewide for the most part), but sounding sirens once for three minutes for an area under a tornado warning is the standard. That is probably true for your area.
I know there is a lot of confusion about sirens. Some people think that when the siren quits sounding, the threat is over. Also, I've heard of locations that sound the sirens for a second time when the warning is cancelled or expired, which also creates confusion.
Sirens are meant to warn people who are outside, with the understanding most people outdoors will hear the siren and take action. It is not meant to be sounded for the entire time the warning is in effect, nor is it meant for people who are indoors. It would be cost prohibitive to place enough sirens in a particular area to assure that everyone indoors could also hear the sirens. That is the job of NOAA All-Hazard radios, the local media, the FEMA app, etc.
If you have questions or concerns, fire away.