Thanks 4u2ges and  Rampa... Between the reply and video I sort of got it working. The scaling function isn't scaling in all directions, but I'll figure that out. I still have legs coming through the dress at times, but at least the dress isn't flying over her head anymore, and I can keep tweaking. Tall Girl #16 and 17 will look better. Just gotta finish them up.

True, however...  I'm certain it would usually be much faster for me to "slowly" bake a good simulation than to spend time manually fussing with collision shapes.  It's not a problem all the time, but when it is an issue, it's really irritating.

I'm not saying they should eliminate collision shapes, but I'd like a more advanced option to be available.

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iClone 7... Character Creator... Substance Designer/Painter... Blender... Audacity...
Desktop (homebuilt) - Windows 10, Ryzen 9 3900x CPU, GTX 1080 GPU (8GB), 32GB RAM, Asus X570 Pro motherboard, 2TB SSD, terabytes of disk space, dual  monitors.
Laptop - Windows 10, MSI GS63VR STEALTH-252, 16GB RAM, GTX 1060 (6GB), 256GB SSD and 1TB HDD

I think the problem with that idea is that it is computationally very expensive. If you've ever tried cloth to cloth collision then you know that it is very slow and sometimes even crashes iClone. 

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I continue to wish for (dream of) the OPTION to use the actual body mesh rather than a handful of primitive collision shapes for the hair and clothing interaction with the character.

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iClone 7... Character Creator... Substance Designer/Painter... Blender... Audacity...
Desktop (homebuilt) - Windows 10, Ryzen 9 3900x CPU, GTX 1080 GPU (8GB), 32GB RAM, Asus X570 Pro motherboard, 2TB SSD, terabytes of disk space, dual  monitors.
Laptop - Windows 10, MSI GS63VR STEALTH-252, 16GB RAM, GTX 1060 (6GB), 256GB SSD and 1TB HDD

This video is useful for tweaking your collision shapes.

Actually the only thing regarding Soft Cloth changed from IC6 to IC7 was the name of the track.
It used to be Soft Sloth and now it is Vertex Animation (new name BTW was introduced with one of the latest IC7 update when RL implemented Alembic Import).
Otherwise, nothing has changed in Soft Cloth Physics since it was introduced in IC6.

What you have to master now, is Collision Shapes.
Collision Shapes are Rigid Bodies attached to character limbs and serve the purpose of stopping cloth from going through the body.
Collision Shapes system is imperfect and it takes some practice to succeed with them. Check the manual.

And some tips not found in help manual:
1. Make sure to start any character animation with Dress (or any other soft cloth)  from a T-pose. Give it 60-100 frames and then start your animation with slow blend.
2. Tweak collision shapes to be below soft cloth mesh but slightly above body mesh. If collision shape is going through the dress in T-pose, dress behavior would be unpredictable once animation starts.
3. Activate no more than 16 collision shapes per character (that includes multiple shapes per limb). Only 16 random shapes become internally active if you enable more than that number (and you'd never know which one would be inactive)
4. Get attached set of Collision Shapes and load it for your character. Those are old type but seems to be better than the latest.Then tweak them approx. match the shape of your female character (there is no need to activate shapes for the body parts which do not interact with soft cloth).

A lot of trial end errors in between tweaking Collision Shapes, weight maps and Soft Sloth Physics settings.

Thanks 4u2ges... that gets me closer, so I can work on the soft cloth part, but IC6 and 7 are working differently. The RL YT instructions are for iClone 6 that had a setting for soft cloth connected to the character, but I'm using iClone 7 and now it appears to be using the material and Vertex Animation for soft cloth - I may be phrasing the wrong, but the method appears to have changed. I've attached a drawing show how Heidi options have changed from 6 to 7, and the frame by frame operation doesn't stop the material and legs from going through each other. I was able to control it a little bit by changing the dress Weight Map brightness, so that sort of works - the dress moves a little weird, but it doesn't fly up over her head.

You'd have to dive into soft cloth physics concept.
You may start here and go down the Soft Cloth Simulation chapter:  https://manual.reallusion.com/iClone_7/ENU/Content/iClone_7/Pro_7.4/20_Physics/Setting_Soft_Weight_with_WeightMap.htm
Also check this video tutorial by RL: https://www.youtube.com/watch?v=rXaiO3wm5NM&t
For weight map examples check the default iClone Dress (in Avatart > Body Part > CC Cloth > Female)

Could someone advise on controlling the movement (physx) of material (clothing) on an iClone 7 avatar. I created a character in CC3 and using it in iClone 7 but I struggle to control dresses. I figured out I could stop the motion by selecting the dress (in the scene tab), and then turn off the activate Physics option (under Modify), but I've struggled with setting to calm down the motion. The dress either flies all over (8 seconds into video below), or it's totally still.