I didn't have any problem with either the Ergo or the Bjorn.

I'm a J cup, and I totally loved the moby for an infant. It is hard at first, but with a bit of practice, it works great, and baby loved it. I was also able to use the baby bjorn too. I didn't really like the ergo, but I know many others do like that carrier.

Beco Butterfly includes in infant insert. Me and my DDs were able to wear it with no problem. The Beco Gemini can be used as a FF carrier when the baby is older but I'm not certain if it comes with an infant insert. I have one I bought used called a Manduca. It's only available in Australia & Europe but I LOVE it, moreso than the Ergo or Beco. The panel has a zipper and can extend longer which is great when they're sleeping, it helps support their head without having to use a cover.

GG and I love the ergo. No issue. Fora newbornI rolled a receiving blanket on the bottom instead of using the infant insert.

I also had a moby wrap for an infant but ergo works too.