I doubt it when it comes to the SGD. Last year the only options appeared to be USD and to a lesser extent Euros.
At first I was a bit annoyed by the luggage porters too. But you have to realize how desperately poor the country's people are. Those guys are just trying to eke out a living. I didn't begrudge them. The tips they are looking for are really small change in the scheme of things.
It's a fascinating place. But you really have to pack your patience. Infrastructure is poor. Vehicles are old. Things take time.