I repeated the suggestion by Stevenson using a closer distance between the electrodes and different cathode position so that it would draw material from the anode nickel wire "wool", and results (again using 10% HCl) were interesting.
Unfortunately experiment duration turned out to be limited. I used 24V and the the cathode was a 0.3mm tungsten wire. Nickel would homogeneously deposit on the tungsten wire as a spiky ball, and at the same time a glow (?) plasma would occur on its tips. Such Ni ball appeared to be quite reactive and readily burn in air at room temperature. Unfortunately the anode broke after a few minutes of testing.
(Video focusing improves after minute 0:33)
EDIT: overall, the reaction side effects (noise, light) appear to be considerably weaker than with alkaline electrolytes, even at 62V (the maximum I can currently apply).
EDIT 2: from the video, interestingly it appears that the anode has bright spots too during the reaction. I was focused on the cathode during the test and did not notice this until I reviewed the video.