Is it Islamically permissible to deal with a Forex company that commits to not taking interest or commissions on open contracts or on overnight positions, allows the use of leverage without commission, and in which gold is exchanged through official daily transfers between the company and the international stock exchange?

What you mentioned is permissible, but using leverage (margin) constitutes an interest-based loan, because the broker stipulates that the client conduct transactions through him in order to profit from commissions. This is a combination of a loan and a compensatory transaction, which is Islamically forbidden. Therefore, its use must be avoided. As for the issue of daily possession, it should be verified. If the broker takes possession of the gold on your behalf as an agent, then there is no harm in that.