There is no excuse for flying overweight. What the aircraft might be certificated for in another land is really quite irrelevant. Is your airplane certificated for that weight? No? Then you're not legal, and have no business exceeding the weight.
Do you know of a surety that another certifying agency has done so with or without structural reinforcements?
Weight isn't just about performance. It's very important, and often more restrictive than the max gross weight restrictions, but there are other concerns. Weight in the fuselage only contributes to a greater wing bending moment, putting more stress on the spars and skins in monocoque or semimonocoque wing. In a turn this stress is fruther compounded, and in turbulence even more so. The load is even more magnified at the upper reaches of the speed limits for the airframe. What may seem minor sitting on the ramp or a straightforward takeoff may be another matter at the design dive limit. An airplane out of the CG envelope may fly fine, but an inadvertant spin may go flat or become unrecoverable.
Regardless of the implications, if the aircraft isn't certificated to fly at that weight, and you're not legal to do so, then you should not, may not, and must not.