The Zetas have answered a question on how bright the 12th Planet will be as it approaches.
Your hope for an early brightness will not be met, as the 12th is too far away for reflected sunlight up until 6 months before passage. Likewise, it does not grow in size to where it is obvious that is not a fading nova at a great distance until it begins to reflect sunlight. Thus, up until these last few months, the excuse that this is a faded nova of sorts will be put forth, and even supported by doctored images. Those few who have been watching the path and know they are being fed lies must support each other covertly, and depending upon the strength of the governments resolve to inform the public to some degree, these individuals may be allowed to present their findings to the public also, in a debate format. However, your best hope of convincing the public in significant numbers will be during the last months, when it is clearly not a nova, and clearly coming closer and on the move.