[MaxMatti]

I'm using namespaced-openvpn to restrict transmission to one network and you could limit the amount of concurrently active files to one, effectively downloading them sequentially. Or do you want to download each file sequentially?

[defrost]

I would hazard they are asking for file-block sequential downloads from start of file to end, so they can start watching a movie while it is still downloading and be assured that the first parts of the moview are present without gaps ...

This goes against the general cluster inter-peer everybody swaps what they have so far w/out reference to file position for maximising transmission within a swarm design of the torrent protocol.