That does seem like a nice pedagogical step. You still get the same sign for enthalpy though, regardless of which convention you use. My observation was really just that, it isn't a meaningful convention in terms of the results you get. (Unlike, say, using a convention that current is the flow of negative charge carriers, which would change all sorts of signs all over the place. That would be crazy...)

Thanks, that makes a lot of sense. Now that I've looked deeper, I actually do have both physical chemistry and physics book that have the dE = dQ - dW convention, and ones with the opposite. So it doesn't seem to be a strict physics vs chemistry vs engineering thing.

Something I noted though, when the convention is dE = dQ - dW, PV work at constant pressure is +PdV, while when it is dE = dQ + dW, work is -PdV. You end up with the same dE = dQ - PdV expression, and I'd guess that all the other thermodynamic quantities end up not being different as well. Does the sign convention really not manifest in any meaningful way? I guess it makes sense that this is such a small detail that I didn't even notice it.

As far as I'm aware, the sign conventions for work are the same. If the surroundings do work on the system, that would be negative work for the surroundings and positive work for the system. Can you give an example of what you mean?