Absolutely. V1.2 corrected the transponder and radio stack logic, so VATSIM controllers will see your Mode C correctly. Just ensure your XUIPC or XPilot plugin is up to date.
The 737-300 represents a golden era of aviation—the transition to more efficient turbofans (the CFM56-3) without the full automation of the 737NG. Pilots must actually fly this machine, managing the CWS (Control Wheel Steering) modes and respecting its quirks, like the infamous uncommanded yaw during go-arounds. IXEG has captured these nuances with surgical precision. -X-Plane 11- IXEG 737-300 V1.2 version download