The statistics for babies being smothered in co-sleeping situations unfortunately include lots of babies who died when people fell asleep on chairs or sofas with the baby in their arms.
The “planned” co-sleepers are bundled in with the wider statistics.
A particularly dangerous thing from a SIDS perspective (up to one year old) is apparently to have the baby sleep alone in a different room to the parent(s).
Regarding co-sleeping, “the most recent studies have shown that most bed-sharing deaths happen when an adult sleeping with a baby has been smoking, drinking alcohol, or taking drugs (illegal or over-the-counter medicines) that make them sleep deeply.” The Baby Sleep Information Source (Basis) - a collaboration between Durham University Parent-Infant Sleep Lab, La Leche League, NCT, and Unicef UK
I personally think this has to be the parents’ decision.
Tales about "stingy" guests and hosts.