I can understand why some would prefer to file even though there's no filing requirement.  But filing a F.1116 would be a different matter, unless, of course, there is no additional fee for that (which would be unusual).

Are you sure the foreign pension is not taxable, especially since you said there's no treaty?  Does that pension account consist only of cost basis with no earnings (and had previously already been subject to US tax in full, which again is unusual)?  Have you considered whether that account would constitute foreign grantor trust (which is subject to onerous reporting with substantial penalties for failure to comply) and the PFIC implications?

I read from your previous post that the social security is foreign benefits.  If that is the case and, as you said, there's no treaty, §86 shouldn't apply.