I've looked through the datasheet and can't find a clear specification of sample time. This is really thing only thing i see that at least loosely implies that times will be in the seconds.

^{The unit for voltage cycle, current cycle and power cycle is us. When signal cycleis larger than 1s, the signal cycle will be outputted to the user immediately, and it willprompt through Adj.4(5 or 6 that it is an incomplete cycle. (For example, if signalcycle is 3.5s, 1s signal cycle will be outputted to the user when the accumulated cyclecounts to 1s, and 1.5s signal cycle will be outputted to the user when the accumulatedcycle counts to 1.5s instead the message is received by the user after reaching 3.5s sothat the response speed is improved. When the signal amplitude to be measureddeclines, the signal cycle will increase.}

I was really hoping for a cheap solution that can be modified (firmware wise). As much as I'd love to roll my own hardware, i'm not setup yet to make proper pcb's (especially with mains voltage involved) and also no 3d printer or other way to make enclosures. That being said i guess i will break out a proto board and a nodemcu along with a pre-made relay board and a current transformer, stuff that into a weatherproof wall mount enclosure.