Hi Maciek:
I prefer the second option, changing the __DEFAULT_PROCESSOR_NUBER definition.
Regarding other members in MQX_init_struct, I think you can change it in user_config.h. These variables are from user_config.h, the default values are defined in twrk60120.h. For example
In twrk60f120m.h we can see
#ifndef BSP_DEFAULT_MAX_MSGQS
#define BSP_DEFAULT_MAX_MSGQS (16L)
#endif
so if you add the following line in user_config.h,
#define BSP_DEFAULT_MAX_MSGQS 20
then this value will be overwritten and be transferred to MQX_init_struct
Regards
Daniel