I believe you're right "Once the DID is received, BUP—depending on the mode, which is determined by various factors—either starts IBL processes from InitScript

I believe you're right "Once the DID is received, BUP—depending on the mode, which is determined by various factors—either starts IBL processes from InitScript (in normal mode) or hangs in a loop, which it can exit only when it receives a message from the PMC, for example as a result of a request to restart or shut down the system." But I am not sure if those are stopped: "Secondly, it starts a whole string of processes; some of them are hard-coded (SYNCMAN, PM, VFS)," Since the authors only mention that the InitScript/IBL Processes are not started, I assumed the hardcoded ones were started, but could be prevented from loading in the following way: "2. In the CPD section of the FTPR, remove or damage all modules except those required by BUP for startup:"