What are specific concerns you have? I've been using the Stream Deck software for a couple of years now and other than a few freezes that required me to relaunch the application. I haven't had any issues.
For me, some combination of it, my Mac, and the software my IT organization runs made it so my Mac wouldn't boot, for one side of anecdata. My experience with the app wasn't as bad as some others here, but I'd much rather use something lightweight (and a multitasker) like Hammerspoon over running their app all the time. It also feels way more natural to me to configure it with a script that I can move between machines, where I wasn't able to find a good way to share config between computers with their software (but admittedly didn't try hard). My deck is connected through a KVM, and it's nice for it to work the same way between my two computers.
From my experience, almost all the functionality with any sort of smarts is designed solely for it's core audience: If you're using OBS and Twitch I'm sure it's fine, but it's general Windows interaction functionality is extremely primitive.
Then there's third party plugins, but I don't really see any security guarantees on how those are designed, there's not a lot of reason for me to be comfortable with those.
The really basic functionality I wanted that the software couldn't change, was the ability to remain functional when the PC was locked.