Launcher output log doesn't follow the same formatting rules as Minecraft itself

Partwise duplicates MCL-1922, but the problem described here is the underlaying problem

The launcher doesn't use the same formatting as Minecraft. One bug caused by this is MCL-1922, another one would be this:

/tellraw @p {"text":"1.\t<--- In Minecraft this isn't a tab, but in the launcher it is"}

This can cause some problems because the way Minecraft displays some text is then pretty different from how the launcher displays the text which makes it more difficult to find something specific in the launcher.