Why do you think 200kgs is "a bit close to the wire"? I've not taken more than minimum fuel for weeks (rounded up to the nearest hundred), not because I'm under pressure to, which I suppose I am, but because there's been no need to.
I wasn't absolutely sure before, but now I am ... so we have clowns out there flying planes who think their pre-flight measurements of existing fuel and calculations of fuel burn to empty on a particular route on a particular day are ALWAYS accurate to within 1 and bit kilos of fuel per passenger
... must be bloody powerful stuff that JetA1 ... I wouldn't try it in my 5 seat diesel ... the donkey might splutter and give up somewhere embarrassing.
Clearly some of these things are not being flown by scientific or engineering minds who easily understand that calculating the size of the likely error in their main calculation is more important than committing aviation on the strength that the man who wrote the manual and the EAA can worry about errors and whether the standard method fits the day. I just knew we'd be bound by now to have a significant number of ex bloody traders in cockpits who know the price of everything and the value of nothing including that of their lives or ours and are prepared to gamble both on their limited mindsets day after day and claim management plaudits for it.