Is It Safe to Undergo a Tertiary Rhinoplasty for Irregular Nose Tip? (photo)

An exam would really be necessary to give you the most accurate advice. In the hands of a specialist, improvements can likely be made with another revision. It is important to keep in mind that with thick skin, you may not achieve the level of tip definition you desire. From here, I would recommend doing your homework and seeking a consult with a board certified revision rhinoplasty specialist who has a great deal of experience. He/she may use computer imaging software to give you an idea of how the final result may appear. Good luck, and I hope this helps. 

Knowing what I know about rhinoplasty and revision rhinoplasty surgery, I do not see anything real obvious that tells me you cannot have further surgery. You need to find someone who is well versed in revisionary rhinoplasty surgery to ensure you get the best possible result. 

I've got to say that from my experience, the outcomes of revision rhinoplasty depend on the amount of scar tissue and the goals.  Safety is an issue depending on what has been done and what needs to be done, but with proper planning, this can be worked out.  The problems that come up, however, can be unpredictable and an experienced surgeon can handle those issues.