Is subfascial BA the best way to improve tubular breast? Or should I still go for submuscular?

Thank you for the question.  
In general, I think it is in your best interests (and that of most patients seeking breast augmentation surgery) to have implants placed in the “dual plane” sub muscular position.  This positioning allows for more complete coverage of the breast implants leading to generally more natural feel/look  of the implants in the long-term. This position will also decrease the potential for rippling and/or palpability  of the implants (which may increase with time, weight loss, and/or post-pregnancy changes).
The submuscular positioning  also tends to interfere with mammography less so than in the sub glandular position. The incidence of breast implant encapsulation (capsular  contraction)  is also decreased with implants placed in the sub muscular position.
Generally,  correction of tuberous breast anomalies involves breast augmentation with areola reduction / mastopexy procedure. The distance from the inframammary fold is increased (to create a more rounded out appearance). Proper implant positioning improves the distance (cleavage) between the breasts. The areola reduction helps to treat the pointed and "puffy" appearance of the areola.
The patient should be aware that the final result will take months to see and that they will need to be patient and that revisionary surgery is more likely than in patients who do not present with tuberous (constricted) breasts. 
I hope this helps.

Subglandular, Total Submuscular, Partial Retropectoral, Dual Plane, and Subfascial are the most common positions for placing an implant.Each has very specific benefits and trade-offs.The subfascial is very popular in Brazil but does not have the same enthusiasm here and in Europe.  Its purported benefit is to add a bit more tissue than sub glandular, but to avoid any of the issues being behind the muscle.But the layer is very, very thin.  I do not believe that layer is thick enough to create a meaningful benefit over subglandular, and the proponents of this approach have not published long term results documenting a low rippling rate.  Nor have they published independently reviewed rates of capsular contracture, the best data for which has always been dual plane.  If your tissue is thick enough it wouldn't be wrong to go subfascial, but you really should consider dual plane.With Dual Plane the upper pole of the implant is covered by muscle, which makes it less visible and adds a thick layer of cover.  But the lower pole is uncovered to a varied and specific extent to allow direct apposition of the implant against the breast only where it needs the most expansion.The key with tubular breasts is that the lower pole gets adequately expanded.  Tubular breasts can have a very mild deformity or a very substantial deformity.  Sometimes an implant alone is enough to expand and reshape the lower pole.  Other times the lower pole needs to have releases done in it from the inside to allow it to expand.  Sometimes a donut lift around the areola needs to be done.Teardrop implants have a particular advantage in tuberous breasts because the area of the breast that typically needs the most expansion is the lower pole, which is also the tightest part of a tuberous breast.  That forces gel to redistribute where you don't want it.  The teardrop shape and cohesiveness of its gel make it very well suited for this, though it is by no means necessary nor always better.I would advise against Mentor implants for it because Mentor implants are less cohesive and have a lower fill volume.  This means they are the most susceptible of all implants to having the volume shift to the upper pole as a result of the pressure of the tight tissues in the lower pole.The bottom line for you is not to take my advice or the advice of anyone else on this page about what incision or pocket or implant type you should get.  You need to see a few doctors until you find one who  demonstrates to you a thorough understanding of tuberous breasts and discusses it with you in a sophisticated and thoughtful manner.  You should also expect to see a large assortment of tuberous breast before and after photos as a demonstration of their experience in this area.  There are some on my website and multiple more available in my office.  Other experienced surgeons will also be able to show you multiple photos.  Good luck --and take your time to find the right person for you.

Thank you for your question.  Honestly without an exam or at least photos this is difficult to answer.  Whether it is subfascial or submuscular is not the end all for correcting tubular breasts.  If you see a few board certified plastic surgeons who perform a lot of breast augmentation surgeries you should get more definitive answers. Best of luck to you.