Should I be writing in American English even though it's not authentic to my stories? I'm starting to feel like I'm isolating a lot of American readers by not using American English in my novels. The largest English speaking audience on the internet is American. I've learnt a lot of countries teach American English as a second language over British English. I can see it working for Blood & Cupcakes as it's in third person but The Small Town Horror is written in first person. Both my stories are set in Australia one in 2012 and the other in 2018, the characters rarely explicitly mention this.
Will I lose part of the character if I use American English over British/Australian English for The Small Town Horror? Would a first-person narrative with a twenty-three-year-old main character work in American English?
Here are links to my stories if you need to have a quick look to give adequate advice: