edit uniform scale curve/keyframes or no uniform scale in the keyframe editor?

I posted this in the Apple forums to no avail, maybe better luck here:

So I'm brand new to Apple Motion but I've been animating for decades. I'm well versed in Maya and from Flash back in the day. I'm simply trying to animate the scale of an image uniformly. I've set keys at two points and then I want to adjust the scale curve to polish up the ease on it. I've hit the diamond next to scale but it seems to always set 3 individual keys on x, y and z. This wouldn't be a problem except that when I go to adjust the curves they're all a bit different. I want to edit one scale curve for at least x and y so that I don't have 2 (or 3) curves with varying slopes causing the image squash and stretch as it scales, as the curves have slightly different slopes.

I would think uniform scaling and editing of the curves would be basic stuff for motion. I found this article on the Apple forum (Can I scale uniformly using the keyframe editor? - discussions.apple.com/thread/5167168 ) but I'm less interested in linking the scale parameters together and more interested in a uniform scale that can have it's animation curve edited while locking the proportions of the image. Make sense?!

Please help! (if you can!)

I find Motion's keyframe editor terribly flawed myself. But here's what I've learned to do when trying to edit graph curves.
Switch off all keyframe graphs except the two or three I want to edit. IN this case, Scale XYZ. Instead of clicking on the keyframe, lasso it. This selects all three parameters and when you pull the handles around, all three are adjusted as one. Works great till you forget to lasso them and try to click on the key. Then you're adjusting the top key, usually X, only.

Hope someone else has a better suggestion for you,and me both.

Motion's main strength is in its library of behaviors. Coming from decades of using After Effects, I struggle with behaviors because, while they're fun and quick, they're so weirdly contrary to everything I expect or want to do while editing my animations and motion graphics.

Your post got me exploring some behaviors and pushing some buttons. There's a twirly on the Scale property and you can apply a parameter ramp behavior to Scale. If you have the keyframe editor open while you make adjustments to the ramp behavior, you can see the effects of your changes on scale curves. Behaviors are weird. Try to have fun exploring.

Thanks for the tip on the lasso. I still think a uniform scale attribute should be motion graphics software 101..wtf Apple?!

So that helped. Dialed in my keys with overshoot on one curve. But...

A second curve in my project is spaghetti. I drag select a key and the handles' angle and lengths are different. I select ALL the different interpolations; linear, constant, etc. I've tried right clicking bezier handles and selecting both align and break tangents and there seems to be no way to reset bezier handles. Which is critical to drag select and not have a jello scale effect...

Know any way to reset beziers in the keyframe editor? Crossing my fingers...

PS- yes, psyched to learn behaviors and wacom support and midi mapping too but right now just need to get the job done. But yeah will definitely be playing with the other toys down the line.