logging pattern

Hi,

Is there a way to set the log message pattern in the new GR logging API (based on spdlog)?  I took a quick look at the code:

https://github.com/gnuradio/gnuradio/blob/main/gnuradio-runtime/lib/logger.cc

and it appears that the pattern is always set to 'default_pattern.' 

Separately, I see that the 'add_default_sink' function is exposed to Python.  How can I use this?  I assume a C++ instance of a spdlog::sink is created.  The pointer must then be somehow brought into Python world.  

Thanks.