I am willing to do it as an experiment especially that the tree has only cost me €2. I'm only going to tease the roots to untangle them and defoliate the internodes to clean up the trunk.Just for clarity, I’ve shared your second following video in relation to repotting or not repotting the tree at the same time, as the OP is not sure on what to do, believing that such work can kill this trees (picea), I have mentioned before in the thread that I’m in support that both can be done (late autumn to early winter) as you mentioned in the video the difference will be that the tree will take longer to respond if root work is involved although they will catch up as the roots develop.