I used P8's morphing tool to "sculpt" her breasts into a sort of smoothed, bridged chest. Then I deleted every morph in her body except for my spandex one and one of the unused PBM channels, in this case #11.  Then I used the free Spawn Character script to create the injection morph in Channel 11 and saved it to the Pose library.

This generated INJ and REM icons in the Pose Library (it doesn't generate PNGs, so I did a render to make my own). Since I deleted all other morphs before spawning the injection morph, the only thing it does to Vicky is add a spandex effect to her chest, which can be dialed to zero when unneeded.

It's usefulness is pretty much limited to the stock V4 chest. Make any change to her breasts, or use a morphed character, and the spandex morph starts to look either too little or too much. Sorry about that, it's the best I could do with my limited skills.

I can't imagine trying to do this with magnets. Sure, you could use magnets to drag her breasts together, sort of like the cleavage morph, but you can't use magnets to make a nice smooth bridge between them. At least, I don't know how.

Rendo seems to be up to their armpits (or breasts) in Christmas submissions for the free section, so it might be awhile before it posts.