Measurement in cooking is a tricky business. Navigating the international differences in basic measurement can be a minefield, especially in an active online world. The Australian tablespoon is a heavyweight, weighing in 1 teaspoon heavier than the 3 teaspoons the rest of the world deems fit which, like our collectively expanding national waistline, seems unnecessary given that 3 teaspoons is a more than adequate (and simple to remember) measurement. I'd defend fiercely our entirely sensible, evened-out 250ml cup measurement, but our tablespoon seems over the top. Paring back, using my nana's 3-teaspoons-as-tablespoon spoon, has been a sensible, and successful move.
Being quite the seasoned mover - at least once every two years for the past (oy) 19 years - I also know a thing or two about paring back a pantry. There's a wonderful passage at the very back of Edna Lewis' Taste of Country Cooking, an eloquent note on baking powder, written in 1976 because her favourite brand was being discontinued due to the 'rising cost of cream of tartar', that I'd like to share a portion of:
For my tastes, double-acting baking powder - the only kind you'll be able to buy now - contains so many chemicals that it gives a bitter aftertaste to baked goods...If cream of tartar is available, good results can be achieved by mixing 2 parts cream of tartar with 1 part baking soda, and using this in place of baking powder in the same amount the recipe calls for.
So, ditch the baking powder and make a batch of your own, I say.