Invisalign refinement - can it be still improved? (photos)

Thanks for sending in the photos, It does appear that you can get some additional albeit minor improvement in the tooth positioning.  A lot of orthodontics is cosmetics and if you are no happy with the way something looks I would let you dentist or orthodontist know about it so it can be fixed.  In terms of the black triangle it is hard to predict what will happen but that can always be corrected with cosmetic bonding after your invisalign is completed. Good luck 

I would agree that your treatment is not complete.  The fact you are on your 3rd refinement tells me that either  your provider is not very experienced (or you are doing a self aligner treatment), or, you are not wearing your aligners as prescribed.  Given where your teeth are now, you should expect perfect alignment and elimination of the dark triangles between your teeth.  If your current provider is unable to provide that service, he/she should refund you some money and refer you to someone more skilled to get the result you deserve.  (provided that your compliance to this point has been perfect.)  Good luck.