You can download the document for free The Constitutional Implications of the NI Protocol 
The Northern Ireland Protocol poses a clear and present danger to the constitutional position of Northern Ireland within the United Kingdom. The European Research Group legal opinion published on 29 December 2020 departs from their own previous analysis, and has concluded that the Brexit deal preserves the sovereignty of the United Kingdom.
There is an almost complete absence of written academic or legal papers from within unionism generally, and loyalism specifically. This stands in stark contrast to the civic activism of the nationalist community, who have rallied the professional class to their cause and used those avenues to make their case through the civic, academic, media and political establishment. This paper seeks to insert an analysis from a loyalist perspective into that sphere, which will at least provide a written record of the arguments advanced against the Protocol.