As temporary partitions they can reduce a substantial amount of mid and high-frequency spill and reflections, ...
I never disagreed with this "in general" but I don't think, ZSchneidi is looking for an occasional, temporary solution in his small 3.6m x 2.5m room and I don't think these blankets will help him reduce the noise next door or the low mids and bass reflections substantially.
Anyway, I tried to help the best I can and if the OP feels comfortable to try 4cm foams or blankets and takes the ridiculous sound treatment in Rabeas room serious … well, then I can't help any further