Safe? No way! 15 degress is the maximum amount of strect allowed with these chains and I would replace this right away even if it means you have to wait for this part to arrive!

I just bought a Wagon with the same problems as your 220D, but the owner thought it would be OK to take it out for a short haul to see if it ran ok and the timing chain broke, busted the crank in 3 pieces, snapped the sprocket off the camshaft and the whole mess dropped into the oil pan, but not before it was tossed into the oil pump drive chain and ripped it off the front of the oil pump breaking the shaft and stripping the pump sprocket!!!!

I bought the car, a really nice rust free model 300TDT loaded with all options including a sunroof and a real nice interior for $500! Now I've got the engine out and apart and already spent $1200 on a new oil pump and other related parts, including a new timing chain! Thank god my camshaft is a lot easier to find than yours will be!

Take your time and do it right! Nothing is more expensive than a cheap Mercedes! And it will continue to be a cheap Mercedes if you start taking shortcuts!