Yes I know of a few I'm in touch with who are either receiving Alloderm or Surgimend in the near future. We also have a current progress report involving Surgimend you can follow as well -->
https://phalloboards.info/forum/progress-reports-the-patient-support-group/10154970-skiman-s-surgimend-journey.html
I believe fillers can be added after, since it was done in Skiman's posts (in particular fat), but this would likely be at the discretion of the physician since these dermal graft matrices are usually one & done type of procedures.
In my opinion, the strongest advantage grafts have is that they're tailored sheets of sterilized tissue, providing the shaft a predictable & uniform look (as opposed to fillers which have an element of unpredictability and often require follow-up visits to correct minor unevenness). Of course on the flip side, it is surgical which will be more invasive and require longer downtime (unlike fillers, which are non-surgical and take about a week to heal from). Pros & cons to both, having them in combination might be worthwhile for some if the performing Doctor agrees. Having them both is also a pricey affair, but if budget isn't a concern, you can reach out to:
Dr. Victor Liu (San Francisco)
who offers Surgimend, Alloderm, and may also inject fillers (fat for sure, others I'm not so sure) in combination. The Skiman Progress Report I linked above is one of his patients.
Dr. Solomon (Philadelphia and Los Angeles)
Dr. Solomon I believe does Surgimend, although I don't know if he's fond of fillers (although he may make an exception for fat transfer, I'm not sure). His website is currently down but you can check out his
Forum Q&A's. 
