Is J Plasma / Renuvion similar to BodyTite?

If there is no skin laxity, adding a tightening procedure is adding unnecessary risk to the surgery. If you have previously had liposuction, there will be some scar tissue and VASER would likely be beneficial. However, both BodyTite and Renuvion may add risks of increased swelling and scar tissue, as well as increased time under anesthesia. As far as the difference, both tighten skin. Renuvion is faster, but is more technique (surgeon) dependent, while BodyTite has more established treatment parameters and is more reproducible but takes longer.  

If you do not have any skin laxity, and your PS does not think that more liposuction will lead to skin laxity, then I would not recommend a preventative skin tightening procedure. Both the BodyTite and Reunion use radio frequency heat to cause fibrosis and therefore skin tightening. I personally use the Reuvion in my practice and have seen some really amazing results.