Can I upgrade my Apple Music free trial (from individual to family) without ending the free trial?

I recently started a 6 month Apple Music free trial. I signed up for the individual plan.

I would like to upgrade to the family plan WITHOUT LOSING THE BALANCE OF MY FREE TRIAL. Is that possible? When the free trial ends, I would then continue with the family plan. (I should have signed up for the free trial as a family plan trial in the first place but didn't realize it at the time.) If I cannot upgrade without losing the family plan, I will hold off on the upgrade at least until my free trial is over.

I've resorted to all caps above because I have seen several people ask this same question and receive non-responsive answers that simply explain how to make the upgrade. As others have observed, however, when one starts the upgrade process, the messages seem to indicate that the free trial will be "refunded" and a new plan will start (implying that the new plan will NOT include a free trial).

Very frustrating as it seems like Apple should want to make this point clear either way.