See CAN 2-703.3
The “manufacturer′s qualified technical personnel” means someone who is involved in the research, development, design, testing, listing, etc. of the product that is being proposed as a substitute or to be used in an alternative configuration. For example, this individual may be a member of the engineering staff for a firestop company who is involved in product:
Development
In-house testing
Characteristics and behaviors under fire conditions
Performance and suitability for the various testing conditions and circumstances
Performance during full-scale testing at the testing laboratory, what its limitations are, etc.
This person is typically not a sales person but he or she is part of the technical group responsible for R&D. He or she may or may not be a registered professional engineer, but may be more qualified to render an engineering opinion regarding their product than a third party fire protection consultant who is paid to review test data, usually provided by this same individual.
Systems that are unusually complex or involve multiple disciplines may require a licensed professional to take responsibility for the proposed substitution or it may require full-scale testing by an approved testing agency. The architect or engineer in responsible charge has complete responsibility for any design alternatives proposed and acceptable to them for their project.