Well, @yeadon yes and no. The new beta firmware should make it easier to integrate HA and the S20 but you can make it work also with the current GA version.
I'll skip the details (unless you want them) but the easy way is:
- Setup your GL-S20 thread network as per your preference (if you need to change stuff) and make sure the thread network is started
- Validate your HA can see the thread network not "preferred" at this point
- Have a phone with the HA app AND the GL-S20 Tool app
- Open the GL-S20 Tool app on the phone and connect to your device
- See the Thread section and flip the "store thread network credential" toggle
- Open the HA app on the phone and access the thread configuration
- You should now see a blue button "Send credentials to Home Assistant"
- After that the GL-S20 should get a "key" like icon
- Now you can make your thread network preferred
- Open the GL-S20 Tool app on the phone and connect to your device
This will enable you to commission thread devices (always from the phone) but note that you'll likely also need to setup a Matter server in HA, depending on the devices you want to connect.
For what is worth, I think the S20 is a very valuable device compact and I like the fact that has a wired connection that allows me cleanly separate radio stacks... I bought a couple more after I realized how to connect the network to HA in order to cover my house better.
HTH.