i think if you think you can make up an insert type thing that it isn't going to hurt to try and save yourself some $$ if it does work. If not you know that is is available and can get one.

I bought the ergo when DS was about 3 and 1/2 mnths, I didn't know about the insert but he wasn't old enough or flexible enough to wear him frog legged so if I have anymore I will buy the insert, mainly cause I am not creative enough to make something.