Most modern web browsers nowadays are using a java script just in time (JIT) compiler to deliver decent performance. This is quite a complex piece of software, therefore around 50% of security problems in a modern browser are related to the JIT implementation.
Microsoft now has turned the JIT component of its web browser off by default in an experiment, and came to the conclusion that users with disabled JIT don't even notice it in their daily work that Java script is now slower. In other words: most users don't need JIT for their day to day work in a web browser.
So M$ now considers to create a super secure browser mode for Edge, where JIT is turned off all the time.
Microsoft now has turned the JIT component of its web browser off by default in an experiment, and came to the conclusion that users with disabled JIT don't even notice it in their daily work that Java script is now slower. In other words: most users don't need JIT for their day to day work in a web browser.
So M$ now considers to create a super secure browser mode for Edge, where JIT is turned off all the time.