I really don't see why not. We're assuming that B executes some sort of periodic motion: half a cycle in the simple case and 1.5 cycles in the next case.But 1) and 3) do not take place at the same position relative to A as the acceleration in the simple case, assuming the same total space time intervals for both scenarios.
The difference in differential ageing between the scenarios must be less than the time for the periodic motion. As with all twin paradox scenarios, there are small variations based on how many acceleration phases B has.
Yes, of course, these are physically identical.To clarify: Are you assuming that A will age the same amount in B's frame during these two accelerations?:
S1: Single acceleration in the simple scenario
E3: 3rd acceleration in the extended turnaround scenario