Translating: Lula could go on probation but deliberately chose to remain imprisoned because he did not '[...] recognized any legitimacy of the process which condemned him[...]'.
The supreme court then ruled that "you can't be jailed until all appeals have been heard". Only then he decided to get out of prison.
I don't think we're disagreeing with each other at this point. He was only actually freed by the supreme court ruling that he could not be jailed until all appeals (of which there are many) were exhausted.
Regime semiaberto is roughly equivalent to being allowed to go out under house arrest and wouldn't have changed his conditions much.
The supreme court then ruled that "you can't be jailed until all appeals have been heard". Only then he decided to get out of prison.