Is Kybella & InMode simultaneously common practice & is it safe?

If removing fat using liposuction didn’t give you the results you wanted then it’s unlikely that further fat removal is going to give you any significant improvement. Don’t expect anything different when doing the same thing. Whether done by chemical fat destruction or liposuction simply removing fat is going to be limited because fat distribution is most likely not your primary problem.
Without pictures we can’t make an assessment but my best guess is your problems are related to the shape and size of your mandible in relationship to the Maxilla.
In particular individuals with a mandible whose body is smaller or lacks projection typically have a platysma muscle the drapes the neck in the more oblique fashion. The primary problem is based on skeletal structure and not fat distribution. And these individuals Liposuction isn’t treating the primary problem and will only give a partial improvement. if it didn’t work the first time I don’t expected to do much by just doing the same thing twice simply using a different form of fat removal.
Get a proper consultation with someone who can give you a good understanding of facial aesthetics.
Best,
Mats Hagstrom MD