Unable to opt into a single group

We have a use case where we want to setup a consolidated list that allows users to sign up for a variety of different mailings which it seems is the preferred approach from a MailChimp perspective. The challenge we have is that the user needs to be able to signup for one of those groups on various different pages without impacting previous subscriptions but the module seems to overrite other selections with blanks essentially unsetting them.

For example, we have our main list with 3 groups of checkboxes for 3 different mailings - Food, Reading and Games. I go to MailChimp admin and check the options under the Food and Reading groups. On my website, I have a page which is showing a block containing the lists subscription form on which I just want to let the user signup for Games. I have javascript running which deletes the groups from the form which I want to preserve (I cannot just check them since I dont know the subscribers prior choices). If I submit the form, this is working correctly in setting the Games group but has a side effect of unsetting the other two.

Is there a known patch or some other way that I can force the code to just update the groups that are present in the form and not force an update on all of the form elements?

Thanks in advance
Andrew