I can only speak from my experience in Scotland with the Children Hospices we have here, but a child in Archies condition with the level of medical support he requires could probably not be moved to the hospice. The hospice staff aim to support in the most appropriate setting which can be hospital, hospice or home and this is discussed with the hospice team in your ACP when the time is right. If the family wish end of life care to take place at the hospice or at home CHAS can support this but it is dependant on the level of intensive support the child needs.
The highest level of support ie PICU usually means that the child's needs are best met and supported in hospital but they can arrange after death to transfer your child to their 'rainbow room ' which is a dedicated cool room where your child can stay and you be with them after death until the funeral if necessary and the family will be supported by the hospice and make use of the facilities. The hospice staff can arrange for hand and footprints, a hand mould, make memory boxes etc - as the hospital outlined in the letter to Archies Mum that they could do. Paediatric PICU's are prepared for this and offer the same compassion and dignity that the hospice will.
My son died at home in my arms with discreet support from hospice nurse and his MDT from the local Children's Hospital. My friends daughter died in PICU in Edinburgh and they were able to spent time at the hospice with her after.
Parents and families who have used CHAS have a common bond in that we have lost our children but all our experiences are different and whether it be hospital, hospice or home, the decisions are based on what is best for the child and where their needs can be best met with support for the family.