Subprocess smart service 'Assignment' configuration and lane assignment in subprocess

I have a parent process (lets say process A) and a subprocess called in it (lets say process B). The subprocess node assignment in process A is set as 'Run as whoever started the process' but in process B there is a lane assignment 'Run as whoever designed this process model'. In this case, on whose security will the process B will run? Similarly there can be a total of 4 cases mentioned below and I am confused that on whose security the process B would run?

1. The subprocess node assignment in process A is set as 'Run as whoever started the process' and in process B there is a lane assignment 'Run as whoever designed this process model'.

2. The subprocess node assignment in process A is set as 'Run as whoever started the process' and in process B there is a lane assignment 'Run as whoever started the process'.

3. The subprocess node assignment in process A is set as 'Run as whoever designed this process model' and in process B there is a lane assignment 'Run as whoever designed this process model'.

4. The subprocess node assignment in process A is set as 'Run as whoever designed this process model' and in process B there is a lane assignment 'Run as whoever started the process'.

For case 2 the process B would run on the security of the publisher of process A and for case 4 the process B would run on the security of the person who started process A (please correct me if I am wrong).

But I am confused with case 1 & 3.

Any suggestions are welcome.