I know it has been asked a lot in the past but I just came back and hear a lot of different stories. Also formulas have been changed a lot in my absence and the guide isn't updated (wiki)
Since I also cannot remember how long it has been since I played dwarf I was doubting too much. KD mates couldn't clarify if they were right or not.

So concerning dwarf +30% BE is it flat rate incr? Ergo

1*0.9 (90% be non dwarf i.e.) * 1.3 or is it 1*0.9 + 0.3.
In other words does 80% BE (non dwarf) means 1*0.8*1.3 = 104% BE (dwarf) or is it simple 1*0.8 +0.3 is 110% BE.

Reading the guide this would matter for both science and dragon effects which makes the Gold dragon less attractive if you look at it from that perspective.