I just started to build something here! My setup so far: Raspberry Pi 4 running Home Assistant OS.
On the GPIO-Pins I have a Module sitting that goes with the name RPI-RF-MOD. Now the Home Assistant-Pi works as a CCU3 base station for all my homematic IP gadgets.
On Home assistant I use the add on Raspberrymatic to connect to different Gadgets (Power Plugs, Thermostats, Window-Sensors) which then again are introduced to home assistant with the help of HACS Homematic(IP) Local.
Now it's working! I plan to automate my thermostats with the HACS Better Thermostat.
It was a lot of reading for a beginner like me. But with small steps and a lot of time everything is actually quite comfortable to reach. And most important: the devices can't phone home, nothing is able to connect to the internet directly.
It's great that it works for you! For me every recommendation of networkchuck that starts with 'and its free! You just have to sign up for...' is a pointer to search for 'open source alternative for...'.
That is how I found out about a Raspberry Pi with pihole and piVPN installed on the same device, using this manual. Pihole blocks ads, with piVPN you can log into your home network using the wireguard protocol.
I thought it was easy to set up, but of course it depends heavily on the time you can and want to invest. So Twingate can be the right solution for you, but I am often impressed by the excelent free software solutions that are out there.