Why a frigate captain might not want a larger command

Could prize money make a frigate captain reluctant to accept promotion to a ship of the line?

Yes. Independent frigate cruising offered exceptional chances for prizes, while promotion to a line-of-battle command could reduce those opportunities.

Frigate captains could intercept merchants, treasure convoys, and enemy cruisers while operating with considerable independence. A successful capture might generate life-changing returns for the captain and crew. Moving to a ship of the line brought status and responsibility but often fewer such opportunities. The 1804 treasure-frigate action illustrates the scale of the incentive, including additional shares for a commodore and the responsible admiral.