No, these are different formats and its impossible to convert them, at least now. And there are no plans to add such converter as I am not familiar with the format nor many other required aspects for such conversion. But we will see, maybe I can make it more regular.
Re flatpak: I am distributing via Flathub. Cannot comment regarding Purism repos.
I have PureMaps installed from the “PureOS Store Beta Repository”, and OSMScoutServer from FlatHub. I can not find the official link for adding “PureOS Store Beta Repository” flatpak repo, by the way.
The mystery continues… Thank you for trying.
As an update to this, some of the mystery has been resolved. Here is link for the Stable and Beta repositories for the PureOS Store: PureOS platform — PureOS App Inclusion Policy documentation
I need to go outside and walk-around or go for a drive to test my setup, but I have managed to download the PureMaps 3.1.0 package from the above repository. I also have the OSMScout Server, package 3.1.1, from Flathub.