I think it's based on reality, as soon as I start a HST service I put brakes on the initial setting so they reduce as the passengers board
Dal they had electronically controlled brakes,a first I think for a UK locomotive. So that might have played a part in the simulation side of things. I do the same as Marc with brake settings. The 43 was the only consist I ran for the first week with TSW4 and I didn't notice till I ran something else.