I've removed Homebridge three times in the past 6 months for just such a rumor. Unless the slowdown is not detectable for weeks, I have convinced myself that MY instance of Homebridge is not slowing down my hub.
It only does two things: send a message, receive a message (over http). It's functionally is nearly identical to Link to Hub. [Subscribe to a buncha devices and then squirt out a message to a "peer".] [Receive a message from a "peer" and do a sendEvent.]
My Homebridge config is tiny as a result of deleting it 3 times Maybe I'm too dense to notice a slowdown. Lazy dictates that I select only "real devices" and not sensors (exception: presence, which HomeKit feeds into Hubitat.) because I have to rebuild the freaking Rooms each time.
I'll have no trouble deleting Homebridge should I need to call for Support, but my perception for MY system is it's not a tragic load.
Every time I have a slowdown, I then realize that I forgot to restart Homebridge after the hub rebooted following an update. I hop over to my Node.js server and can see “Invalid API call” repeating. Stop the instance, reboot the hub, wait a few minutes, restart Homebridge, and all is normal again.
my Homebridge is running on a Mac and is autostarting via LaunchCtl. I've never restarted homebridge/node.js coincident with a hub reboot yet, as far as I remember.
Like my hub itself, I never seem to need to restart Homebridge other than when changing devices. One of the recent improvements Tonesto7 made was to have the restart button in the App. Meaning I haven't looked at the service running on the Mac in weeks.
I did recently upgrade that Mac to Mojave and had trouble with that. Since getting it going again, I haven't looked at Homebridge -- 'til yesterday.
I have three platforms defined in my config.json: a Thermostat, and both of my Hubitat Hubs. (The 2nd one doesn't work properly, but it's defined, nevertheless.)