I was in touch with Particle regarding the publishing rate and here is their response:
Matthew - Particle Support (Particle)
May 5, 09:55 PDT
I was able to briefly review your code and the cloud side logs for your device.
If I am understanding the code correctly, it appears that whenever your peripheral ever has a signal readout, you have a loop that will publish 4 events minimum each iteration.
Per our documentation here :
NOTE 1: Currently, a device can publish at rate of about 1 event/sec, with bursts of up to 4 allowed in 1 second. Back to back burst of 4 messages will take 4 seconds to recover.
If my understanding is correct, the conditions in your loop allow for multiple loop iterations to publish, thus, it would be absolutely possible to exceed this limit and put your device into a rate limited state.
Rate limiting would absolutely have an impact on the timeliness of services such as IFTTT. It is also wroth noting that the free tier of IFTTT is known to have considerable delays as well in certain conditions, and may also be catalyzing the undesired behavior. If time sensitivity is a concern, I may consider pursuing other services in addition to reducing the publish frequency of your code.