But if there's a good reason to switch to QImage on a Mac, who knows.
On one hand, I think we're in, "If it isn't broken, don't fix it" territory. In other words, if your current workflow works, switching to something else may be a waste of time
On the other hand, it didn't take me long at all to discover a couple important benefits that produce a noticeable improvement (to me anyway).
The problem of Lightroom crushing my shadows is not minor. If I can confirm that with a few other images, that alone would send me to a different tool.