Could armament or crews explain a supposed port restriction?

Could something other than hull material explain the supposed restriction on East Indiamen returning to Britain?

No convincing alternative is established. Armament was similar to that of other ships, and the larger Asian crew share on regional voyages is raised only as a doubtful possibility.

The claimed restriction on East Indiamen returning to Britain is revisited after the discussion of teak. Their armament appears to have been much like that of comparable ships, so it supplies no convincing explanation. India-China vessels often had a larger proportion of Lascar or Indian crew, but that possibility is also treated doubtfully. A company paying for expensive ships had a reason to keep them usable across its business.