WebGL game crashing after some time in firefox

I am developing a racing game for webgl platform. Game will run smoothly on higher end systems but not in low end systems. I have checked with unity profiler also and I have attached the same here. I have attached the images with respect current game build size. Anybody please help that how to optimize the game in terms of size and performance.

Only in Firefox…

Even in chrome also it will crash but compare to firefox I can play longer time in chrome.

Pinging @Joll she is busy so maybe not see this.

Y8 Games