Anyone have feedback on the VISM vise block?

So I've stripped probably 4 buffer tubes when attempting to tighten them down. Always the end plate eating the threads on the tube when I barely over tighten. Yes, this is usually with cheaper milsepc tubes. There's no way I get close to 30-40 ft lbs before it slips and cants the tube. I'm wondering how budget manufactures like PSA are torquing their tubes down. Has anyone used this jig and can give me feedback?

So I've stripped probably 4 buffer tubes when attempting to tighten them down. Always the end plate eating the threads on the tube when I barely over tighten. Yes, this is usually with cheaper milsepc tubes. There's no way I get close to 30-40 ft lbs before it slips and cants the tube. I'm wondering how budget manufactures like PSA are torquing their tubes down. Has anyone used this jig and can give me feedback?