If your orthodontist says that your smile is hard to correct through Invisalign, I would trust his opinion. Invisalign has it's limitations despite what the advertisements and media say and I have several patients who have been dissatisfied with their final results! I have corrected hundreds of smiles like yours but I prefer not to use bonding unless you want a short term fix. Please consider the option of placing porcelain veneers on all four front teeth which will allow the doctor to "borrow" space from the other front teeth and give you four front teeth that appear symmetrical with central incisors the same width and contour and lateral incisors the same width and contours. Porcelain veneers are durable, rarely need repairs or patching over time, and remain color stable!
I wonder why your upper right front tooth is so out of alignment? It is very unusual to have that tooth move in that direction on it's own! I would have your bite or occlusion evaluated to see if there is a lower front tooth alignment problem that is causing that upper front tooth to move. If the bone support around those upper front teeth is good, it is to your advantage to endure braces to get those front teeth and your bite in proper alignment! It is true that the tooth could be extracted and a bridge and crowns could be done, but if your bite is off, you will fight that problem for the rest of your life with excessive wear, broken crowns and teeth, loosening teeth and possibly TMJ complications! Make the decision to invest in your smile with the right choice for a long term solution!