Stretch/Squash with armature only, not mesh deform modifier?

I have a character that needs to slightly squash the body while at the same time allowing use of its’ complete rig. I thought mesh deform modifier would be the best way to do this, but if I apply the mesh deform, it acts as a second armature and the existing rigging is basically unusable. I tried using a stretch-to modifier on specific bones, but then the bones stretch with almost any movement, and I only need stretching under specific conditions, not always. The only solution I can think of now are is a shape key that will stretch the body. Any other suggestions on this that I haven’t mentioned?

if you use the mesh deform you can’t use the armature on the rig as well (you will get double transforms)

so use the armature on the mesh cage (not the mesh)
you can use a shape key on the mesh or the cage
or possibly the stretchto constraint on one or more of the bones in the rig

another way (there are always several ways to do things)
is to use a shape key on a mesh deformer cage - if the mesh deform modifier is above the armature modifier in the stack, changes to the mesh cage (eg- shape key) will effect the mesh BEFORE it is deformed by the armature

Using shape keys on the mesh deform is a great idea, thanks! I haven’t tried it yet but it’s on my list…