yes, you can wait to have soft tissue work done.
I was 56 when I had FFS along with extensive soft tissue work done by Dr Rossi in Argentina ( you can find my thread on Susans ). The surgeon's liaison, Amanda, said best process would be to do bone work; forehead, chin and jaw, heal, then return for soft tissue work. All procedure, bone and soft tissue, could be done at the same time, but results would not be as good, though still an improvement. I chose everything at once, for several reasons. I really did not want to go through surgery twice, plus taking time off from work. Also, while waiting for healing process I'd actually look worse, the bone work would be done, but now the skin would be even looser. I was okay with the lesser results ( 80% ) from doing everything at once because I had a lot of age related / sun damage to my face.
Having said all this, 8 months on I am very happy with the results.