https://leehite.org/Chimes.htm is the best source of information I've found on chime design and length. They go into great length about the lower octaves and how you can hear them (or not).

The linked site acknowledges Lee Hite actually. I suspect it's not a crowded field :)

The suspension point calc is particularly neat, I suppose putting it at a null node in the tube vibration so it doesn't damp it.