For @planner, this script can be placed in the "Global Footer" widget area (or any other widget area present on all pages). It overrides the ajaxify method and returns anchors to their default operation, which is a regular page load.
However it seems Markdown Fireball doesn't support named anchor tags?
I know a plugin was created for this (nodebb-plugin-anchors)
but the plugin link seems to be down, and I would not use the plugin before knowing if it's still compatible..
Yeah I imagine it would be fairly straightforward. Just add a new rule for ctrl-b and then check if the textbox in composer is active. If so take selected text and wrap it with asterisks using this module