So we have support for these in our binding today, and at the time i added this, we were the only vendor yet to support it, but thats changing soon, at CES there were a number of products announced with TBR matter clusters in them, so they are coming.
There is still work todo here i"m sure (i need more time to play with this stuff), but the foundation is there and i’m using it today to manage my 2 TBRs. The real value, at least to me, is being able to manage multiple TBRs with the same config (operational data set) from one place. This allows multiple TBRs to participate in one logical network which is awesome.
Configuring TBR parameters in openHAB (esp32 TBR running the official matter chip build)
TBR actions
Unfortunately its not so much Thread 1.4 related, but Matter 1.4 related (unfortunate both projects have been releasing with the same version numbers, but no relation to each other). I’m 99% sure it does not include those TBR clusters, plus i don’t think it exposes itself as a matter device.