Dovin objects to the clumsiness of the crackdown rather than to the idea that the Consulate should possess the inventions. Tezzeret keeps Rashmi's work for himself and places the remaining devices within Dovin's reach.
He identifies the Gatewatch's care for weaker companions as an exploitable flaw. At the same time, he reassures inventors that their devices will be treated well, while allowing no meaningful refusal of the transfer.
The chance to catalogue and study the collection quiets his doubts about Tezzeret. His self-description as precise and reasonable cannot make that reasoning neutral. Security restrictions, curfews and aether control serve the ambition of a person who sees a city as a system before he sees its unwilling participants. Dovin raises principled objections to Tezzeret's public dismantling of the Fair, yet accepts the premise that the state may take every invention without its maker's agreement. His interest in organizing and studying the seized devices helps quiet his doubts. The polite official gratitude is therefore part of how coercion becomes a routine administrative procedure.