Cradle position support

Hello everyone, a different question from usual: my 8 weeks baby fall asleep only in this position after several minutes of cuddling and walking. As you can imagine after half an hour or more the arms and back star to suffer a lot so I'm searching for something than can support the baby and a little just to make him fall asleep ONLY in this position and the transfer him in a different location while sleeping. I think of something like the second photo but certified and from a trusted brand. We tried different carries (baby Bjorn, ring sling, bands, ecc), brand and type, but he hates all of them. We were supported by 2 expert and they have said that we're using them perfectly but sadly he doesn't like to be held in carriers. Do you know a support that can help us? We'll always held the baby with both hands, always, but we need a help for our arms and back. It's only for make him fall asleep and don't destroy our arms. Thanks.