4036 - It is not in the Chabad tradition for the Rebbe to give a recommendation letter.

Yet, your work to gather the rulings of the codifiers is vital, especially considering that many copies of the works of the earlier rabbis have been lost, and the study to understand the Halacha with its reasoning has diminished. So, convey my opinion orally, and I'm confident that Chabad Chasidim will support you. https://www.torahrecordings.com/rebbe/igroskodesh/012/004/4036