Like this?Have you tried to make a prolapse bra? or maybe it's called it a vetwrap bra or vetwrap sling? There was a clever article or thread on here where someone was using vetwrap and a modified yoga pants leg (stretchy tube) to keep prolapsed vent inside a chicken - they actually had her in a sling inside a dog crate where she could just barely touch the ground (couldn't push it out or get away or flap). I don't have the link to it, but have you seen that? Might help keep the prolapse inside when you can't be there in person.
https://www.backyardchickens.com/threads/successful-vent-prolapse-treatment-with-photos.1101406/