I own two of these, and yes, they're quite limited.

The MSP430(BT5190) in this watch (requisite to run the CC2560 Bluetooth chipset) is a bit more than the MSP430 in the EZ430-Chronos.

The MSP430BT5190 comes with a FreeRTOS port. (Very) Likely this is what is used for the Fossil watch as well.