1) While synthetic oils can be used for engine break in, they will also extend an engines break in period. In fact some of the new very expensive German cars come from the factory with Synthetic.
2) Synthetic oils are mre slippery than standard dyno oil, just go to any of the manufacturers sites and compare their wear & shear test results.
But really, doing your 1st changes at 250 km (or miles) is about the same as holding your wallet open at 100 mph. There is absolutely no need for it. As long as you follow a manufacturers recomendations, and even use crap Suzuki Dyno oil, for the next 100,000 miles, you would see very little difference in Engine life. (I know this because a good friend of mine is a Petroleum Engineer who works for a major oil company & see's all the test results).
Now my friend who I mentioned tells me that just about every oil in a bottle will be fine for obtaining maximum engine life, but the key is service intervails. To make a long story short, your Bandit can be made to run just as long with a dyno oil versus a Synthetic oil, but to achieve this you would have to do more frequent changes with Dyno oil, as it will break down faster.
PS: I use Mobil 1 MX4T in my Bandit as I was able to view some shear factor test results done with Motorcycle specific oils, and Mobil 1 came in 1st over competitive products. (But not by much) By the way shearing of oils polymers occurs in the transmisson mostly)
Don't be fooled by oil marketing departments as just about everything out there in a bottle is more than enough to give your Bandito a long & happy life.