They appear to be invisible! Can you circle them?
C1B provides you an option to add extra decoupling should you wish. It is listed as a NS ( no stuff) so it isn’t present on the demo board. Whoever designed the board at MPS thinks it isn’t required.
Decoupling is a bit of a mystery to me.
R6 allow you to adjust the voltage at the EN pin, the EN threshold is pretty accurate and you could use it to create an undervoltage lockout. For example if you didn’t want your circuit to operated at Vin of less than 9V you could adjust R6 to achieve that. C6 is just a noise filter.