There is a common myth that you are a "slave" for 6 months. That is simply not true. Yes, the standard rule states that after receiving a new Residence Permit, you cannot just switch employers during the first 6 months.
But there is a solution. If you end up in a bad company or find the conditions unbearable, you don't have to suffer for half a year. I can process not just a transfer, but a completely new Residence Permit application.
It will cost more because new state fees apply, but it gives you the freedom to leave whenever you want. Your peace of mind is worth more than a few fees.