Im not sure about this, Im dithering a bit. Do you mean fit into the mouth in one go or in a couple of bites!!! You know what they are like with some foods such as bloodworm, dried flakes or half peas. If they dont go into the mouth in the first bite, they swim around with them still in their mouth until they can get it in! Im also finding it difficult to gauge exactly how big the platys mouth is. They definitely wont be bothered by the endlers though. Also the fry differ in size a bit. I will post some photos.
Anyway, I will leave it a bit longer as theyre my babies!