Umbilical hernia rubbing

I've just encouraged a friend with the wonders of fluff but she's having problems working cloth nappies around his umbilical hernia, he's 4 months, and is prone to explosive poos, can you recommend a particular cloth nappy with a low rise or umbilical space that isn't newborn sized? I have the smallest kissaluvs but I reckon they're too small for him. She's finding tots flexi the worst for fitting at the moment...

Motherease sandies could easily be folded down. Or if she had a snap pliers she could easily add some snaps and make it like a NB snap down bit.

If she's willing to buy new, I'm sure almost any wahm would be able to adapt their nappy to have an umbilical snap added.