If a process’ memory usage continues to rise without limit as long as it is running, it is almost certainly leaking.
Sometimes memory usage appears to grow for a few hours and then peaks, but if it continues to grow indefinitely without bounds there is almost certainly a leak. Xcode’s tools are good, but they are not foolproof and they can be turned off. If the leak occurs indirectly because of the way a library that JUCE wraps is being used (rather than directly as a result of allocation in JUCE itself) then Xcode’s tools will never detect it.
I refer you to this discussion from 2013: ComponentAnimator memory leak
In this discussion you initially made all these same points, then did some investigation and wrote:
“Ok… doing some digging, it seems that there’s an issue where the Images that ComponentAnimator uses are being deleted while the GL context is no longer active, which means their textures can’t be freed, and they get leaked. I’ll get on the case and sort this out…”