If the numbers reach enough to create a "critical mass", then perhaps whomever steps forward to "represent us" might do the following.
Use the emails to ask all of those who have "signed up" the one or two things they would most want the BoD to do that they are not doing?
Collate the list into the top 3 or 4 priorities to start with.
Research just what legal & fiduciary rights the group can use to encourage receptiveness from the BoD
Make contact with the company and prepare the groundwork for that list to be presented "forcefully" using those legal & fiduciary rights.
Negotiate an outcome.
We need an advocate, a "champion" as it were to manage the group to effect the best possible outcomes,. Preferably someone with knowledge of shares, mining and company administration, who will understand and interpret the BoD responses on behalf of the group ... to a level that means even the very unsophisticated "mom & Dad" investors can understand at the simplest levels and negotiate to achieve the change we want to see.
Like Me.