Please note that we've updated the Mount & Blade II: Bannerlord save file system which requires you to take certain steps in order for your save files to be compatible with e1.7.1 and any later updates. You can find the instructions here.
I was just thinking that earlier today! 100% support this idea. If we or a companion has good smithing, why shouldn't we be able to "fix" weapons, as you say, removing negative modifiers and/or adding on positive modifiers?
yes this would be a good addition, at least allow us to repair the items, removing negative modifiers
speaking of "repairing" items, I'm experiencing a bug that resets all the modifiers from items in my inventory (sadly it remove the good modifier too), but I don't know how to reproduce it, I simply leave negative modifier items in my inventory and wait till they loose the modifiers, pretending that my men had done the repairs in their spare time