Re: Help me find an AIO that fits a LARGER 1 year old...needs to be SUPER absorbent!
I've never tried the Simplex because I'm so gunshy of "OS" now, but I will offer a second vote for Nana's Bottoms. She will customize them, but to be honest, I think it might be hard to get them clean if you added too many more layers than what she offers as her standard. I got mine with bamboo and asked her to leave the back open as a pocket to add a doubler (and to turn inside out as they dry way faster that way).
There are 4 layers of bamboo fleece standard which lasts my heavy wetter about 1.5-2 hours (but he pees through even overnight disposables, so very heavy wetter).
With a small hemp doubler at front, he can go about 4 hrs. I never have leaks or wicking around the legs, which I was worried about initially because these diapers do not have encased leg elastic. They can be completely soaked but won't leak.