I tried to use the s40 lite but had lots of issues. I added 4 and they would work for a while and then stop responding and have to be physically turned on to control them and some of my other zigbee devices would not longer work. Tried changing zigbee channels and no luck. I put them on ST and they work fine. I ordered these to try and see if they work instead https://smile.amazon.com/gp/product/B09KNDM4VV/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
Also you can look at this thread, looks like others have had better luck.
DEAL: SONOFF S40 Lite 15A Zigbee smart plug - Anyone use these? - #10 by garyjmilne