Does the Bicopter mode setting set the flight parameters according to the TAILSIT setting or the OctaQuad mode?

Does the Bicopter mode setting set the flight parameters according to the TAILSIT setting or the OctaQuad mode? Do you have a good heart tell me?
Q_TILT_TYPE = 3 Bicopter

Thank you very much for your reply
At present, I just follow your reply and complete the setup, but there is a very strange problem. The left and right steering gears are tilted backwards by a smaller angle than the forward tilting angle, which does not meet my settings.

Bicopter mode, very sensitive to the center of gravity of the aircraft

the back tilt is between trim and servo min/max depending on reversal, the forwards tilit is between trim and TILT_YAW_ANGLE parameter. The other min/max is the forwards flight position.

Yeah, very hard to tune

Thank you for your answer.