Oil scalp, heavy dandruff, with MPB. Will I still have loose hairs after HT because I would still have dandruff?

Dandruff or oily skin will not change if you have a hair transplant surgery.  Dandruff or oily skin has nothing to do with hair loss.  Transplanted hairs will not be affected by dandruff or oily skin.

Both these conditions can be treated by a dermatologist. Though many people believe they are a cause of hair loss, the medline indexed pubmed research has not shown this to be the case. You should get a dermatology consult and also consider a hair transplant consult.

So do many people before and after a hair transplant. Dandruff is best treated with good shampoos like Head and Shoulders shampoo