Ok, I get the point about there being more wall space for desks etc, hadn't thought of that.dont get me wrong we have WIR in each bedroom, so I'm definetely not against them, just don't like those teeny tiny WIR, that end up being so small they are useless. 1.7m is a reasonable size, so probably ok.
(hoping they don't have a shoe fetish my like my 17year old DD )
my calculations give you 1.7+.7 of hanging/shelves/drawers space so 2.3, but .5 of that will be the corner. If you did a whole wall back to back of built ins, then you would have 3.6m of hanging space, but lose some wall space. Or you could do say 2.4 of robe then 1.2 of study nook area, which would give you more sqm in the room cause you would have a separate desk area.