@Dawn *******
we are from Canada and my application was done online through the Thai embassy in Ottawa. So I can only speak to that.
When I submitted my application they asked flights because it is a multiple entry. I submitted the flights except for the end of the 6 months. I also submitted a travel plan along with an explanation of why we did not get the last flights. I told them that at this time we are not sure where we are going, either Canada or leave a month earlier and go to Cuba.
I was concerned that they wouldn't accept that, but they did.
We arrive in Thailand in 2 weeks.