Seriously? I salute you...
Seriously. I'm aware that's more than necessary, but cheap oil is, wait for it - cheap.
The drain plug isn't sitting at the lowest spot of the Mini R56 N16 engine oil pan.
Even the GTI's EA888 3G shows a delta of about one quart between total oil fill and
oil change quantity (5.7 l vs 6.6 l total). As a conclusion some flushing seems relevant
as it'll flush at least some of the remaining dirty oil out, perhaps half a quart/liter or
so. I wouldn't go that far and recommend this approach to the public though. Just
wanted to let you know my reasoning.
@NitroM3: Is this a B48 engine?