Can a lower ranking person award a written counseling to a higher ranking individual based on "positional authority"?

No. The rating chain is the rating chain and if you do not rate them than you obviously cannot counsel them. We have this problem in aviation with officers who out rank their platoon leader, however the officers out ranked cannot be rated by their platoon leader. Usually it is defaulted to the Executive Officer and he catches all the senior ranked NCO's and officers who were/are not up to snuff leading the element regardless of echelon. When an issue with a senior ranking Solider, Officer, NCO occurs, the supervisor by position should use the rating element to properly counsel the individual. Some commander's support placing the best in the right position regardless of rank and other prefer to place the senior regardless of performance in charge. I prefer talent management. A war story from way back, personally I was a Specialist as a MP when the Provost Marshal approved me to be the Desk Sergeant for all patrols which contained SGT and SSG personnel working the road. Under command authority by position I could dispatch and have them perform duties, but I could not counsel or discipline them. Just my .02

Had to read this entire discussion several times to get it straight in my mind, then took it back to the basics to get what I consider the correct and legal answer. In one word, No. I recognize, and do not question instances where such "counseling" may have occurred, but I do not believe such incidents would be regarded as official. My thought process follows:
The military survives on juniors following the direction, or orders, of seniors. It is the senior's responsibility to ensure directions given are legal and necessary. If a junior individual is directed or ordered to accomplish any act they consider a danger to the material or operational accomplishment of a specific task or mission of the unit or section, it is their responsibility to formally refuse the order. If the order endangers the unit or personnel, it is the junior's responsibility to ensure the act is not accomplished by the senior or any other person in the area the senior might order to do it at risk of court martial. The senior has two options to settle the issue. They may put the junior put under arrest and proceed with their desired action, or, time permitting, ask for the reasoning behind the junior's refusal to execute the order and defer to the junior's reasoning if appropriate.
If the senior elects the arrest and has his order executed, the junior (positionally responsible) individual is relieved of any responsibility for the consequences and the senior is inescapably responsible.
If the senior's action results in the adverse results anticipated by the junior, the junior ends up being a witness before the commander in support of the senior's incompetence or lack of judgement, which will reflect in his official record over the commander's signature. If no adverse results occur, the junior will be the defendant in front of the commander and have to defend his actions.
Fortunately, a situation such as this is mostly handled less formally through the intervention of department personnel equal to the senior, or who are recognized by the senior as having expert knowledge that allows the senior to back down gracefully, hopefully with an apology to the junior who was placed in the situation.
Why should an junior with "positional authority" be placed in such a predicament? The senior is assumed to have situational awareness that would override normal procedures and has the authority to order deviation from the normal rules under which the junior would operate in such circumstances.

The only time I have seen it done is at Professional Military education. But I don't see why it could not be done in other situations as long as the relationship is defined as part of the counseling.