Noida Extension upgrade: Legal doubts are real

Visited a few projects in Noida Extension last weekend, including some by VKG Group. I'm currently in a 2BHK in Sector 137, thinking of upgrading to a 3BHK or a small villa, but the legal side is giving me serious doubts. Meri main concern hai builder ka track record, especially after reading about older projects like Supertech Aadri. How do you guys actually verify a builder's legal history beyond just RERA registration? Kya red flags hain jo common buyers miss karte hain? I'm looking at properties around ₹1.5 Cr near the FNG Expressway, don't want legal hassles later. Title verification ke liye kya steps hain jo most log skip karte hain? Is RERA complaints process actually effective for project delays in Noida Extension?