Transform effect is one of the most powerful thing Ai has, compared to whole Repeats functionality. It’s versatile, it works with anything (unlike Repeats).

It has some flaws though, and one of them is the fact it always operates on the overall bounds of the objects, even if it is clipped. It can be useful for some cases, but most of the time we treat objects differently.

Check the image attached.
This combination of effect options applied to a clipped ellipse should produce a result like the green one at thee right... instead, the object is reflected from the right side of the circle inside, not the mask!

At the same time, if one decides to flip it from it’s left edge — Ai should not do it from the bounds of the clipping mask, the way it does now, but the circle!

Again, both can be useful.
So — please make it as an option!