wouldn't that concave the bumper like outwards? like, wouldn't it bend outwards more?
inwards... outwards... whatever way you need to go, to get the bumper how you want it to fit.
you gotta remember, that when bumpers are shipped from the manufacture, they are stacked on top of each other, and may bend if left in this position for several days during transport... or shipping to your address from the shipper... this is normal and why its ALWAYS recommend that you take your kit to a PROFESSIONAL for installation
Professional = bodyshop with much experience at installing aftermarket body kits and other such pieces... not just any normal bodyshop who only specialize in insurance claims and accident repairs