explicitSwapControl ，commit is not essential ？

In the Emscritpen api docs, the explicitSwapControl say :
If explicitSwapControl is set to true, rendered content will not be displayed on screen automatically when event handler function finishes, but the control of swapping is given to the user to manage, via the emscripten_webgl_commit_frame() function.

https://emscripten.org/docs/api_reference/html5.h.html?highlight=offscreen#c.EmscriptenWebGLContextAttributes.explicitSwapControl

but i set explicitSwapControl is true , and adding the linker flag -s OFFSCREEN_CANVAS_SUPPORT， run in chromeV111 ，i don't use commit , the rendered content still display on screen .

the demo in :
https://github.com/yangfangfang1204/offscreen/SuperRenderMT2.cpp

the compile script in :
https://github.com/yangfangfang1204/offscreen/readme.txt

the 704_576.yuv is a 704*576 yuv data.