Hi Michael,
Currently, it isn't possible to use anything other than your company's legal name here. As you mentioned, following the publisher page update, we show the publisher name for any organizations verified as a trader and with the established publisher badge. The reasoning is that we need to be sure that the text we show on the publisher page is legitimate, and we don't currently have a way to automatically import or manually review alternative names.
This is definitely something we're actively discussing and we may make changes in the future as a followup to the initial publisher pages launch. Unfortunately, there isn't anything I can suggest currently, however.