Trapeze Harness for kids - recommendations

Anyone have any recommendations for trapeze harnesses for kids? my oldest (of 3) is now 6, my nephews are 7 and 11 and I'd like to start getting them out sailing with me more and getting on the wire is a lot of fun. (safely, mostly with both hulls in the water at all times, for the little's, a little more adventure for the 11yr old.) are there any youth harnesses that are adjustable enough to fit a range of small bodies, and more importantly grow with the kids?

The magic Marine smart harness is available in an XXXS but it seems according to the size chart, to have a very narrow range in terms of body types that it fits. I'll be able to use any harness i get for a couple of kids, but I'd still like to be able to adjust it to fit so it will last for a few years for each kid as they grow. We don't get to sail all that often, normally a week or two in the summer so I can't justify spending hundreds of dollars on new harnesses every couple of years for the kids.

any experience with sailing with kids on the trapeze and recommendations for harnesses would be appreciated. I haven't found much in the search hence the post.

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1987 Nacra 5.8
1978 Isotope (sold)
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