If you look at page 3 of the datasheet, you will see that Watchdog Timeout Period will be within a set range. The MAX6369 (and its related products) guarantee a minimum tWD of 10 seconds and a maximum tWD of 30 seconds when the part is configured for a 10 second delay. There is no fine-tune control in this 10 to 30 second range. The tWD will vary within this range from part to part. For example, one MAX6369 may have a tWD of 15 seconds, and will always exhibit this 15 second tWD behavior when the SET pins are configured for a 10 second tWD, while another MAX6369 may always exibit a 20 second tWD under the same SET configuration. There is no way for the customer to fine-tune the tWD time themselves.
This applies to all Watchdog Time Periods and all Startup Delay Periods for the parts in the MAX6369 family.