^^^^
This is incorrect.
The FILE SPLIT - ON/OFF option only controls whether or not you can manually split the file anytime while recording by pushing the REPEAT A-B button. (unless the hold switch is activated of course)
The recorder automatically starts a new file when it reaches whatever max file size setting you've selected (using the MAX FILE SIZE setting), until the card is full or the batteries run down, regardless of the setting above. You do not need to do anything to 'activate' the automatic split feature.