timppu: That is possible and I didn't test that specifically now (starting several GOG browser downloads at the same time; I might test it later if I remember)...
...but I doubt it, because from the past I recall that increasing the number of download threads in e.g. gogrepoc.py does not increase the total download speeds either for me. (It is still better to have 2 (or more) download threads so that when one file completes, another is already downloading which can instantly use the bandwidth which is freed up by the completed download). I usually keep the number of download threads in gogrepo at 2 or 3, the default is 4.
Threads per file, which is what I was talking about, can have a different benefit to multiple files being downloaded at the same time. I seem to recall that Galaxy does one file at a time, whereas I know gogrepoc will do multiple files at a time, unless you modify the streams to be just one, as I used to do back when I was using it. For me, soonest downloaded has always been the best policy.