[Wikitext-l] Have multiline tags not terminate the list item until the tag is terminated

Lists in wikitext are a pain. Proof: number of duplicates of https://bugzilla.wikimedia.org/1581. Aryeh Gregor proposed in 2007 an amendment that would IMHO solve many problems and find no opposers in principle, "Have multiline tags not terminate the list item until the tag is terminated": https://bugzilla.wikimedia.org/show_bug.cgi?id=9996#c5 Does someone disagree? How hard is it to implement? (Probably rather or very hard, but who knows.)

For more general context of how I was brought to this problem, and to discuss alternative solutions for my specific issue, please refer to https://meta.wikimedia.org/wiki/Help_talk:List#List-agnostic_markup_insertions instead.

Nemo