I have an external 32MHz xtal connected to pin 21 and 22. I can change the schematic/configuration to facilitate the higher baud rate. The datasheet mentions about 115200 baud rate and I need at least 230400. Would be great if we can achieve higher.
Using the examples with and without the wireless connectivity framework it was possible to set the frequency of your interest in the KW41. For example, if you are trying to use it in the wireless uart demo you will need to modify the following files.