I got it working with HomeEasy now (without needing IFTTT).
Thank you MichaelD for inspiring me to look for a software solution rather than buying a bunch of new products.
I looked at Domoticz yesterday and to my surprise it's very easy to set up now, unlike when I looked at it 5-6 years ago. I brought out my spare Raspberry Pi and spare RFXcom, copied Domoticz to the SD card and that's it, it's ready to add devices. Then I saw in its wiki (which was very bare when I looked at it a number of years ago) and there's a detailed page to make it work with HA-Bridge, so Alexa thinks these are Philips Hue lights!
Very easy. Just gotta add the rest of the HomeEasy devices now
