Once you are using interoception activities regularly you will develop a better sense of connectedness to yourself and to others/the environment around you. Becoming aware of how your body feels and responds can be a bit strange initially and it takes time to be comfortable with it. However, it is amazing to know how you feel or how you are responding to an event or other stimulus (sensory input/person around you etc). It is also very powerful to know when your emotional state is changing before it hits fight/flight/freeze, so you can actually prevent your meltdowns from occurring (though you may still need to process the event or experience in order to ensure meltdown is not merely delayed a bit).
When you know your emotional state is changing you can respond to that change in helpful or unhelpful ways. Helpful ways will be ways that lead to less stress and fewer difficulties, unhelpful ways increase issues and emotional distress. For example, when I know I am starting to get angry because my fitbit signals a huge increase in my heart rate, I can choose to ignore the signal or react. My reaction could be to do something distracting and/or something to bring my heart rate down or unhelpfully to yell at the person I am getting angry with. Yelling is unhelpful because it should not be the first step in trying to solve an emotional discord, walking away or getting a drink of water or casually doing an interoception activity with my feet (or hands under the table) or a breathing activity are helpful because they will prevent the build up of anger and focus me on connecting to myself and enable me to connect to others.
Give it a go using the resources – even if you just pick one thing to do once a day and then try to see how much more aware you are of your body during that one interoception activity over time.