XF 2.2 selectively use markdown conversion?

[sub_ubi]

I know Xenforo has an internal markdown->bbcode function. I turned it off as it interefered with older posts. But I want to use it sometimes, specifically when posting messages from the API. Any guidance on how this could be done, or would it take a modification?

Ultimately I'm trying to post a CHANGELOG.md as an update message.