Two points. The first point is definitely needed. The second point would be helpfully but would not be necessary if a massive common use demand for gold bars was created, such as the example I provide below.
1) Additional but more common uses for gold bars need to exist. With exception to LMMs and SOTLs, gold bars are exclusively used within the Hideout. Adding GBs to all ships will create a small demand, but for GSing to be worthwhile, there needs to be a large continuous demand for GBs.
As a suggestion, we could have a tiered influence purchase, such as a player can purchase up to say 50k influence in a port using gc. Once they reach that influence level for that port, influence must be purchased with Gold Bars. This would cause a massive demand for gold bars especially for those who hold or want to hold lots of influence.
2) As Danik suggested in reducing costs of GS creation, GB costs, or both.