We had a problem with getting dimming to work properly with "insteonlocal", as it was at the time Chris wrote the driver, which runs as a plugin to Homebridge. and created it as a hybrid, connecting both directly to the hub for smooth dimming and fast-off, and to the Insteonlocal plugin for on/off and status if I remember correctly. Since there was a lot of overhead in Homebridge at the time, that tended to be slow and not fire on occasion, or it wouldn't refresh properly sometimes. So we asked Scott Kuester if he would separate them out and he kindly did. Worked amazing. Then Chris asked about web sockets for instant refresh, so he added that too. That's where we are currently. Now working on 8 button keypad.
This setup has been super fast and reliable for me. The Insteon-Server application as you can see now is nothing difficult for a Pi to run. I run on a Macbook Pro with other stuff, so lots of HP there to spare. I don't have a massive number of Insteon products, 12 in total. Small house. I've shared it back into Homebridge using the driver from @dan.t and it's super responsive. No refresh problems anymore. Much better than when it was integrated into the Homebridge plugin
If you run the newer Insteon parent and child driver Chris wrote, once all your devices are saved in your config.json file, you just click Initialize in the parent, and it will auto create all the children. You also won't have to enter their deviceIDs as you do in the older driver linked to in this post.
Without knowing how many Insteon devices you have, if you're a long time Insteon user, you know how great they are. No worrying about losing pairing like Zigbee and Z-Wave. The dual mesh is very reliable, so it's just amazing with the compatibility and strength of Rule Machine 4. I'm able to integrate a massive amount of devices with the tools available from Hubitat and the community here.