No they don’t.
Haven’t tried this, think it should work but why would you need to? Its public IPs.
I have only ever done this on vultr where the primary IP assigned to the WAN interface of the fusionhub is always in a different subnet to the subsequent IPs I add to passthrough over PepVPN.
I had assumed that vultr must be adding routes for the additional IPs with the WAN IP of the fusionhub as the next hop (so Layer3). If Scaleway specify the need for MAC address assignment (which smells like L2) then maybe this won’t work, but the original example has all the IPs in the same /29 so perhaps it should work - guess you’d need to give it a go and see and then let us know!