I see, homemade weapons of high tiers get some debuff separate from the manufacturer multipliers. I've never heard about this and can't figure out what it is. I'll try to find it and remove it in the future.

My meito sand sabre hase less damage than tier 3 from shop. The same goes for other weapons

This mod removes the manufacturer modifiers, so your smithed weapons should be identical to any available in shops of the same grade. Let me know if this isn't working.

Why my weapons wors than from shops? Even thoght it`s slighly has less wieght, around 2 kg less