But
[1]TUSBXXXXhas already been ordered
[2]debug guide of this controller demostrates serial port initialisation where it is stated that SMOD for 11.0592MHz should be 0 and 1 for 24MHz and 48MHz.
in addition this example gives time delatys calculation for 11.0592, 24, 48 and 96 MHz:
#define BAUD4800_11059 256–(28800/4800) // 250
#define BAUD9600_11059 256–(28800/9600) // 253
#define BAUD4800_12000 256–(62500/4800) // 242.9791666
#define BAUD9600_12000 256–(62500/9600) // 249.4895833 don’t use
#define BAUD9600_24000 256–(125000/9600) // 242.9791666
#define BAUD9600_48000 256–(250000/9600) // 229.9583333
#define BAUD9600_96000 256–(500000/9600) // 203.9166666

Is it OK to non-integer delays for baud rate?