I'm with a woman who weighs 465 and she can't stand jeans the denim is just too rough. She has a girlfriend who makes her stretch leggings and she loves them. Now she knows how I admire her belly so around the house she will pull the waist down under her belly. I really like how these leggings show off all her curves in the thighs, calves and ass.
Generally speaking it seems like the fellas like the waistline under the belly and the ladies prefer over the belly. I still wear my jeans like a 90s kid with the top of my boxers sticking up over the belt line and my pants sagging a bit, and my belly definitely hangs way out over the top - I can't imagine trying to hoist them up to my bellybutton, but maybe that's just me.
I have to go with under the belly. This single mother just moved onto our street and she wears her stretch pants under her belly and she has a tremendous belly hang and she is quite comfortable letting it all hang out and I'm glad she does.