Meh, from a mod point of view it's a pain in the ass. Most of the custom weapons are wallies and it takes several times to get it approved. Checking CW is truly a pain and on top of it all it's one of the most subjective customs to check in terms of OP or not OP.
At this point every person can only make one custom weapon and that weapon can be tied to both of his bio's, no matter if it's canon or custom, Uchiha or Kaguya, Minato or Madara. On top of that other people can give you their CW, however those weapons can only be summoned and thus count towards the 3-jutsu rules + you can only use one CW in a battle.
In all honesty I don't care much, however you only give one argument in favour for it and I find it not really an argument. First time I heard that people make CW for the purpose of placing it on one unique bio. People make CW just because it's cool to have a weapon and yeah they want the weapon to be unique but I have never heard of anyone saying he wanted a weapon to one unique bio. Yes I made a unique weapon for one unique bio, but I have had the same bio for ever and only one, however only a very small amount of people has done that. Most RPers have two bio's and they regularly change, so saying that you want to tie a weapon to a unique bio is pretty much not true if you change from bio regularly. Then it's not unique anymore + there are some people, though less, who often drop their CW to make a new one, so that makes the weapon not unique either.
At this point you already can tie a "unique" sword to a "unique" bio, you're not obliged to tie it to your other bio. The only difference with your proposal is two instead of one CW. All the uniqueness is IMO just BS, no offense, if you change from bio often. You can hardly call it a signature weapon from that bio if you change it, then it becomes your signature weapon, not the bio, and then one weapon would be truly unique.
Now it just seems people want to get more weapons, even though you can already have a large amount.
