I like the mini's, too, but don't wear them very often for the same reason.
With the longer pouch, I fold the bottom of the tail upward and tuck it into my undies. My pouches have a velcro closure, too, and you don't have to worry about
the velcro coming undone, even if it's not tucked into your underwear. It holds really well, and I've never had one come undone in the 3+ years that I've had an ileostomy.