To be honest, and this is just my opinion, but the whole system seems dependent on who processes your case and what kind of day they have had when your file comes across their desk.
As far as I see it, other than the money spent in fees to apply for the visa (as well as lawyer fees as needed, which I do not think it truly necessary), what do you really have to lose versus what you gain?
Sure, in theory, if the banking in Argentina at the official rate is enforced on not just rentistas, but pensionados, then you can make a choice later down the road to leave and go somewhere else and apply for a visa in that country.
At the end of the day, and again, this is just my opinion, your desire to reside in Argentina should extend beyond just the financial benefits afforded to you as a foreigner via the blue dollar.
*If* your only motivation in being here is because of how your buying power is extended versus what it is in your home country, then go somewhere else if you disagree with the requirement to bank here at the official rate... which of course is a true unknown.
In the end, you will either be asked to do so, or you will not.
It could happen now, or, if not now, then maybe when you apply for renewal after your first year of temporary residency was approved... or maybe never.
Who knows what the future holds. That is why everyone here lives in the moment.
Which, if in the future, if that requirement is asked of you as a pensionado after having already been here at least a year on your visa, then you can either leave and go somewhere else, accept things as they are and bank at the official rate, or, switch your visa type to a student visa, apply, and go to school for a year (for free, for now) until you have reached the two-year threshold and qualify for naturalization (which is two years as opposed to three for permanent residency).
Most likely, if you are here in Argentina on a pensionado visa, you are not looking to work. You are only required to pay taxes on work sourced in Argentina, not benefits you are entitled to, especially if those benefits are tax-free from the U.S. federal government (in the case if SSA or VA).
Of course, banking in Argentina at the official rate, while not a tax, does decrease your buying power, (which would be even more the case if you were banking here AND paying taxes on income earned here).
Remember, in the case of SSA and VA, it is not, as far as the U.S. government is concerned, counted as earned income. It is unearned, or passive income.
In the case of SSA, it is an entitlement, based on your ability to work, while VA is compensation for your military service and illness and injury incurred in the line of duty.
The VA cannot make you better for your sacrifice, but they can give you money to help ease your pain and suffering.
There are always a work-around to every problem in life, you just have to be bold and creative and courageous enough to try.
Remember, ask for forgiveness, not permission.
Good luck.
