PM> Install-Package Equals.Fody

[Equals]
public class Point
{
    public int X { get; set; }
    
    public int Y { get; set; }
    
    [IgnoreDuringEquals]
    public int Z { get; set; }
    
    [CustomEqualsInternal]
    private bool CustomLogic(Point other)
    {
        return Z == other.Z || Z == 0 || other.Z == 0;
    }
}

public class Point : IEquatable<Point>
{
    public int X { get; set; }

    public int Y { get; set; }

    public int Z { get; set; }
    
    private bool CustomLogic(Point other)
    {
        return Z == other.Z || Z == 0 || other.Z == 0;
    }

    public static bool operator ==(Point left, Point right)
    {
        return object.Equals((object)left, (object)right);
    }

    public static bool operator !=(Point left, Point right)
    {
        return !object.Equals((object)left, (object)right);
    }

    private static bool EqualsInternal(Point left, Point right)
    {
        return left.X == right.X && left.Y == right.Y && leftt.CustomLogic(right);
    }

    public virtual bool Equals(Point right)
    {
        return !object.ReferenceEquals((object)null, (object)right) && (object.ReferenceEquals((object)this, (object)right) || Point.EqualsInternal(this, right));
    }

    public override bool Equals(object right)
    {
        return !object.ReferenceEquals((object)null, right) && (object.ReferenceEquals((object)this, right) || this.GetType() == right.GetType() && Point.EqualsInternal(this, (Point)right));
    }

    public override int GetHashCode()
    {
        return unchecked(this.X.GetHashCode() * 397 ^ this.Y.GetHashCode());
    }
}