Suppose I have cast Aid on 3 of my allies, and those allies have all dropped to 0 hit points and fallen unconscious. I would like to get all of them back on their feet as quickly as possible. Can I cast Aid again to restore 5 hits points to each of my 3 allies who are already under the effect of another Aid spell?
I know that spells of the same name don't stack, so my 2nd casting of Aid won't increase their maximum hit points any further. However, it's not clear to me whether the hit point increase from Aid is any different from the healing provided by spells like Cure Wounds, so it's not clear to me whether there is a stacking issue that would prevent this from working.