I have been using Rogaine or a generic for about 10 years. My hairline receded only slightly over those years. I only applied it to my crown, and this area did thin over time. However, I believe Rogaine helped me keep hair, and retarded my hair loss in both areas.
I just had a HT Less than a month ago, and I will be using Rogaine and Propecia(generic).
Since my HT, I have switched to brand name Rogaine foam. My doctor told me that Rogaine helped prevent shock to surrounding hair and that after waiting 14 days post op to resume its use. The foam is much better than the generic liquid I had been using. The foam stays were you place it, and then it gets massaged into the scalp. Also, I used to get very dry, flaky, and itchy scalp every 4-5 days on the liquid. I have had none of those symptoms from using the foam.
It would not hurt to add Rogaine foam to your treatment plan. I have been applying small amounts of each dose to the new transplant area along the hairline as well as the vertex.