There is now a Sonoff-Tasmota add-on for Home Assistant which allows management of flashed Sonoff home automation devices
I have not yet tried flashing via this new community add-on but it looks really useful considering I had to manually flash and setup all the Sonoff devices on my home automation before.
It was really easy to set up and get going on Home Assistant: Just click to install, let it finish installing and startup, and then clicked on "Open Web UI" and that as it. I did have to specify the IP address range to auto-scan as my Home Assistant is running within a Hassio container which has its own IP address range. But after that, it detected my connected Sonoff switches.
addon-tasmoadmin - TasmoAdmin - Community Hass.io Add-on for Home Assistant