Suggestions Please: A Kilt, ASD, Sensory Issues/Input

[Lady Grey]

Hi
I’m seeking some suggestions from the Rabble.
If you, family or friends are on the spectrum I’d love some feedback, hits or tips for kilt wear

I’m working with a young teenage man with ASD, we’re pottering along nicely but he has moderate to high clothing sensitivity issues and the behaviours caused by that are not the most socially acceptable.

He loathes anything tight or restrictive around the groin to ankle area. Thus loose elastic waist track pants are worn at half mast aka plumbers crack. I remove his underwear when we’re working together and I’ve got him some long line hipster Tee Shirts that cover the buttocks... but still those hands wander ... a lot!
I’m not sure about the waist area as so far he’s never worn anything up that high and pulling his pants higher up to his hips just results in them being pulled down and down

So with the warm weather arriving down under I thought I’d try making a kilt for him.
Wool isn’t an option so I’ll use my preferred stretch drill that I’ll pre wash multiple times to soften it. Hopefully the liner in a very soft cotton will help (I’ll leave out the hair canvas)

So I’m looking for suggestions and adaptions in the design to help stop/prevent the wandering hands?
Maybe 3- 4 buckles + Velcro? Sew down the under apron on the inside?
I’m going to try him with US style cotton boxers underneath that he can wear at half mast under the kilt (fingers crossed) they aren’t generally worn in Australia other than as sleepwear so I don’t think he has tried them before.

Any suggestions, comments, stories, experiences welcomed.