I think that ‘noöne’ is the logical next step from the (widely viewed as permissible) ‘no-one’; OTOH ‘noone’ would just be wrong. Keeping it as two words would

I think that ‘noöne’ is the logical next step from the (widely viewed as permissible) ‘no-one’; OTOH ‘noone’ would just be wrong. Keeping it as two words would be like writing Rechtsschutzversicherungsgesellschaften as rechts shutz versicherungs gesellschaften, which would obviously be terrible