I have been using Shelly devices for quite some time both on our boat, off grid, and also as HomeKit (HK) accessories via Homebridge (HB).
I was really amazed when I found that some smart guys have created a software package that replaces the stock, official, Shelly firmware with the "Shelly-HomeKit" package which emulates a "native" Apple HomeKit accessory.
It's very nice done, really simple, and the flashing of the software is done over the air (OTA) with your ordinary WEB-browser.