I disagree about seam sealing a Hilleberg tent.
I didnt do my Akto but when I had to set up my tent in running water at one end and a small pool at the other, the corners of the inner started to seep water, not badly, but enough. I contacted Hilleberg and they said that I would need to seam seal the corners( they did offer to send me seam sealer for free).
Also had to seal the fly, up near the small zip at the top of the door.
This was where the tent was set up when it started to leak
Roger