Are wrote:Correct. HP are the one resource the 15 minute workday generally does not expend, since the party uses their big guns right off the bat.
I don't really see what healing between encounters has to do with the "15-minute adventuring day". That concept comes from groups who expend all their primary resources (high-level spells, x/day class abilities) within the first few encounters, and don't wish to continue since they no longer have access to their most powerful spells/abilities.
Since between-encounter healing is typically performed using plentiful low-level resources anyway, I don't see how this could do anything with that particular problem.
And even when they do, there are always Wand of CLW.
As I said above, all this change would really do is save you the cash for happy sticks.
And pretty much require a character with Cure Minor Wounds in every party.