Anyone have recommended source for hi-starts these days?

I see https://www.aerofoam.com/highstart-bungees.html Still has top quality products for sale.
https://www.aerofoam.com/highstart-bungees.html

I see Tower is still selling one but no specifics.
https://www.towerhobbies.com/cgi-bin...?&I=LXHNZA&P=7

I see Amazon has a silicone rubber hi-start for sale. 10 meter section. The old Latex were usually stretched to 3x their rested size. This claims you can go to 6X but no info on how much pull that produces. The suggest you can launch a glider up to about 6.5 pounds.
https://www.amazon.com/Bungee-Silico.../dp/B01N8XHUWI

Latex rubber up to 58 feet long
https://www.amazon.com/Rubber-Tubing...E4F&th=1&psc=1

Hobbyking has 10 mm Silicone rubber
https://hobbyking.com/en_us/hobbykin...tart-cord.html