We're not talking 'just' 30kg though. It's 30kg directly over the front axle. It may not sound like a great deal, but the car is setup to deal with varying weights in between the axles and over the rear, not over the front. It will likely make a noticeable difference in my opinion.
Adding that amount so far forward does change the dynamics of the car. Not only will it change the weight distribution significantly, but it'll also change the polar moment which affects things like turn and and under/oversteer characteristics.
Adding 30kg on the front axle will alter the distribution from 41:59 to 42:58. 1% doesn't sound much, but it does in reality make a big difference which is why the DSG will have different springs to the manual. When you're developing a car, a 1% change in weight distribution would be incredibly difficult to achieve. There's not a lot in a car that weighs 30kg on it's own that can be moved around, and car batteries are fairly commonly relocated in performance cars to achieve better weight balance/polar moment....and that's only a fraction of a %.
I wouldn't say it would be unsafe, but it'll certainly not control the front of the car very well and will likely make the car more nose heavy leading to more oversteer.