I thought so. But I had to say it, because seat harnesses have been suggested many times.
Still, the chest harnesses you've selected are unsuitable. Look at the way the straps cross in the back, rather than using a single
wide horizontal belt; they are meant to be used ONLY in combination with a seat harness for holding a climbers weight in towards a rope
and not to hang from. They are not safe for any other purpose. If you hang from one, it goes slack and comes off over the shoulders. Sorry, but this is not a healthy choice. I have climbed thousands of days over 30 years, have used all sorts of harnesses, and I recognize that some gear
A chest harness for sailing can be very cheap
to make. A simple band of seat belt or 20" climbing webbing around the chest, high under the arms, with 2 rings in the front will do. Add shoulder straps, only to keep it at the right height, and you have a custom fit harness for peanuts. I've even tied harnesses of this sort from rope
, when a crewman didn't have one. It is all about the fit. But I would NEVER cross the straps in the back, as climbers do (I have used that style climbing).
The kids climbing harness would certainly work
. I used a very similar one with my daughter, rock climbing and ice climbing, until she grew. Perhaps it is overkill, not very comfortable, and prone to rejection by the kids.
I should add, I suppose, that I used to run a small company making climbing hardware
and webbing gear