We did BLS here too for the most part. However, we did intorduce foods one at a time. She ate a new thing by itself for abotu 2 days - this is important to guage her reaction to them - you never know what she may have a reaction to, but if you are isolating foods for a short while as you first introduce them, you can accurately see what reaction she is having from what food.
There are no food allergies in my family, so we werent very strict with many things, but she doesnt have ot be allergic to something to have a reaction.
Charlotte has a topical reaction to eggplant that is quite severe - if I wasn't isolating foods I would have had no idea what caused that reation until I worked through an elimination diet (PITA)
HTH