Same setup here except I use Opencore Legacy Patcher so I’m on the latest OS as well. Works amazingly well.

I never questioned the limitations for these upgrades…

Thanks for reminding me that everything is possible, I may try Opencore to keep it even longer !

How’s the performance? I have 2013 MBP with 16GB RAM, and am curious if the newer OS are more RAM hungry.

It’s called zigbee (soon to be Thread). It’s wonderful. And if you set something up like home assistant with ZHA or zigbee2mqtt, then you can use most zigbee products together with just the one coordinator (instead of being tied to only ikea or only hue, etc. or using multiple hubs).