These look very nice. If you’re in the EU or UK, Siegenia, a well-known maker of lockable designer window handles, has now released a Matter over Thread version. They should work locally with smartthings without requiring any custom code. Battery powered. They will also work on some patio doors. Cost is about €90.
Available in white or “anthracite“ (dark gray).
Also available from Amazon in Belgium:
This is exactly the kind of device I was hoping we would see once the matter standard was adopted. A niche use case, but very applicable to Home Automation, and available to work with smartthings, and HomeKit, without custom code or a bridge device.