Even if this did work for plain lists it won't work for headlines because headlines have an arbitrary number of stars and thus it is not possible for the grammar to know what is a sub-headline vs "the next headline". For a similar reason I'm fairly sure that the sublist approach will not work due to issues with relative indent. Here is the quote from the current draft syntax.
> An item ends before the next item, the first line less or equally indented > than its starting line, or two consecutive empty lines. Indentation of lines > within other greater elements do not count, neither do inlinetasks boundaries. The "the first line less or equally indented than its starting line" section is what prevents your approach from working because you have to know the relative indentation in order to figure out which list contains a nested list. As written your grammar will parse a nested list into a flat list. This is because there are an arbitrary number distinct tokens that could be =indent= in your grammar and the EBNF can't specify an ordering for them so that you can't say that one indent is greater than another. For list termination the rule seems to be two new lines followed by not a list element. As a result of this, my inclination is to only parse plain list elements and reconstruct the whole "list" only as an internal semantic. Check the behavior of 1. to 1. see 1. what 1. I 1. mean 1. 1. 1.