Increasing precision of logged timestamps

[TomeWyrm]

I was wondering if there is a way to increase the precision of the timestamps recorded in the FML logs. I don't need to improve accuracy, I don't want to introduce overhead, I just want [12:39:32] to show [12:39:32.XXXXXX] or whatever number of digits is appropriately significant.

 

Using another launcher would be fine if one of them can give additional precision, but I'd prefer knowing if Forge/FML can do that natively. If not does anyone know of a launcher that can intercept the logs and output that data to a text file with maximum timestamp precision?

[LexManos]

Just configure Log4J however you want.

[TomeWyrm]

Where in the path do I need to place the log4j2.xml file? I've tried a few places that seem logical, and none of them are working.