Based on its contents, https://w3c.github.io/compute-pressure/#rate-limiting-change-notifications seems to have been added before https://w3c.github.io/compute-pressure/#dfn-may-receive-data, as the former says "inactive windows" should receive updates every 10 seconds (and does not take workers into consideration) whereas the latter's focus checks should prevent other windows from receiving updates at all.

Furthermore, there is nothing in the data collection algorithms that prevents an observer's sampling period from being < 1 second, although the only existing implementation of this API currently implements this limit at the pressure source side by polling the platform every second. From the text, it's not clear if this should be done at the pressure source level for all windows and workers or per-window/worker.

(It's also important to keep in mind that implementing any rate-limiting per-context needs an Automation-related note, as at least in web-platform-tests we need to be able to fetch and process data more than 1 per second to test the rate obfuscation algorithms without taking too long to run the tests)