Just be aware that smartthings is in the middle of a major architecture change, and the Samsung-hosted free groovy cloud will be going away soon, along with everything that runs there, which includes the groovy smartapp that makes the current homebridge integration work.
So far I haven’t heard of anybody who’s going to write a replacement. A few people are planning to do smartthings to home assistant and then home assistant to homebridge, but that’s a lot of work.
And it doesn’t sound like matter is going to help much in this specific situation because when smartthings announced their plan for matter it’s one way: they’ll be able to bring mattercompliant devices into the smart things app, but they are not intending to have a smartthings hub act as a matter bridge, so smartthings-connected devices won’t show up in HomeKit that way. 
So just something to be aware of before you spend a lot of time and effort on it.
See the following discussion thread. (The topic title is a clickable link)
And in case you missed it, here’s the official announcement on the planned architecture change: