Note that NEC 250.64(E)(1) addresses grounding electrode conductors in enclosures and general ferrous raceways (not just conduit).
More to the point, the installation - at least in my opinion – should be focused on performance and not semantics about what is or isn’t a conduit or an odd shaped box. The intent of the NEC and the 607 standard is to avoid reducing the effectiveness of the grounding conductor when in proximity to ferrous metal. In that case I would say that you should bond the conductor at each end (or end of chain as the case might be).
A related bonding/grounding standard, ANSI/BICSI N3-2020, clarifies an ambiguity in the ANSI/TIA 607 standard by adding the following regarding multiple short sections in series (less than 3’ each) of ferrous conduit:
“Where multiple short sections are placed in series for the conductor run, they shall also be bonded at both ends as their collective length would exceed the 0.9 m (3 ft) criteria.”
