Decided to try iOS lockscreen today to see if it works any better, big mistake it’s just nearly broke my system setting the volume to max as soon as I engaged it. Frightened the life out of me and likely the neighbours. God knows if it’s done any damage to my speakers. No other app has this issue controlling volume. This is just silly how longs this been out and still no fix. They really need to sort out completely broken features like this. Why is it using the phones system audio level? No I didn’t have volume limits set as never needed them on this system. Lesson learned
I don’t seem to have that issue with my 7th gen iPad. I guess It’s another one of those Roon mysteries; why it works well for some users and not others. 
I noticed it’s still listed as a beta feature even after all this time. My guess is nothing or not much has been done to this feature since it was released a long time ago. 
No me neither. All I did was active it, and boom 100% volume. Luckily I had a remote handy to mute it quickly. It seems to adopt the volume that the system iOS is set to which is very very bad.
It plagued me last year and even with the automation workaround issued by Connor, I ended up getting an Android remote.
My last few outings with my iPhone 13 saw the phones volume go to a 100% but thankfully not the endpoints like before. Lock screen control wasn’t on though, so maybe this is a newer bug.
Edit: lock screen control is on 
Hope nothing is damaged.
Scared the sh1t out of me when it happened last year.
What automation work around?
Correction, it was Benjamin
I also had it set to reduce the volume upon opening the Roon Remote app, just in case
None of this should be necessary. If its not implemented properly it should be removed or fixed.
Completely agree with you.
I didn’t move to Android last year due to this, but it may have influenced my choice.
Off topic:
Still waiting for Ubiquiti to fix the Unifi app for Android. That’s been 6 months now.