To be honest it’s almost best to remove the flaps Vs putting in 3D printed. On average the material used for 3D printing is not likely to hold up to the huge amount of heat and stress you’re going to have in the intake. Consider there is already so much stress on the OEM unit that they broke.
Taking a risk on something that is going to be subject to less ability to resist melting and heat along with structurally weaker. The issue you worry about is the parts breaking off and then ending up in the motor. Now what starts as a possible cheap fix ends up being a requirement for a new motor.