I would say, unless you're an experienced mix engineer stay well away from any kind of Stereo enhancement.
Those things can do more harm than good in inexperienced hands.
If needed let your mastering engineer widen your mixes.
But experience starts somewhere, and experimenting while simultaneously seeking mentoring is a fast track to becoming experienced. After all, mastering engineers started with no experience.
OK, you seem to disagree with everything I say, fine, but I'm trying, as are you to help the OP and everyone else who reads this thread.
I'll explain my statement: If the OP learns to make his mix sound wider/ better by NOT using stereo enhancement then he will have learned a valuable set of skills that will make him a better mixer in the long run. He/she will then be in a better position to use stereo enhancement if still needed.
I would say the same about using maximisers/limiters and mono testing.
Using these things from the get go as a lot of inexperienced mixers do is like running before you can walk.
I'll put this into perspective by saying I've been doing this for 30 years and have learned a lot on the way, I'm still learning and happily passing on what I've learned from working with Grammy award winning producers/engineers/musicians hands on, NOT from reading books or theory.
Mr Patanjali may I ask how long you've been a professional mix engineer/Producer/musician? I'm just curious as to your credentials.