Technically it is kind of the same, but with different set of configured features.
Already a bit oldie,
"Mac OS X and iOS Internals: To the Apple's Core"
https://www.amazon.com/Mac-OS-iOS-Internals-Apples/dp/111805...
Unless I missed something and the DMA requirement is along the lines of "having to allow other browser engines as long as they don't bring their own JITting Javascript engine", no, it literally can't.
And you know, you’re one web search away from finding the page where Apple directly mentions access to a JIT for alternative browsers: https://developer.apple.com/support/alternative-browser-engi...