Bursting is not a goal in itself - it is just a side-effect of using cheap and simple latex or rubber balloons.

You fill the balloon so it has slightly positive buoyancy. As it rises, it encounters lower outside air pressure, and expands to match it. Eventually it will rise to an altitude where the pressure is so low, that the latex is stretched beyond its limits and bursts. Typically at about 40km and about 100x expansion in volume.

To prevent bursting, you need a more complex material that will expand many times at first (to allow the balloon to rise to operating height), but will then stop expanding without breaking.

Or perhaps some sort of venting system that engages at a certain altitude or pressure preventing the ballon from over expanding. Like a hot water tank has a pressure release it the tank gets too hot will vent releasing pressure.

Venting does not work. For a given altitude, there is no amount of helium which will make your craft stable unless the volume of your craft is non-linear with pressure (usually done by having something that stretches to a limit, and then cannot stretch further)

Or just use zero pressure balloons.

https://sites.wff.nasa.gov/code820/spb_differences_between_z...