Increase in Boss weapon upgrade cap

I think that boss weapons could be much more viable if they could be upgraded to +6 with the boss soul that they were made with (obtained in a later playthrough) allowing them to be further upgraded with demon titanite to reach +10. While some are certainly quite powerful, I think this could be an interesting option for players to have, since otherwise the boss souls that can only be used for one weapon (Priscilla for example) have to be used for currency, if used at all, after the weapon is made ias there does not seem to be much point in having multiples of an identical boss weapon. This could also make boss weapons with higher requirements (greatsword of artorias for example) much more worthwhile, as I have heard repeatedly that these weapons are often irrelevant for any focused build (build revolvng primarily around 1 or 2 stats). I was wondering what other thought of this idea.

I F*cking love the idea! However if the rate of power increase up to +5 remains the same when upgrading up to +10, some weapons will probably end up being a little tóó powerful. Little being an understatement.
So it would probably need some balancing, but the idea is great.

Nope... Completely insane. Boss weapons would be incredibly OP... 890AR DSS No thank you. 900 AR CB Woah there Lesley! Nahh, dude sorry that it isn't very merry to say that the idea would seem deranged.

It's an interesting idea, but like Amos said, it would be imbalanced. As they are, boss weapons are well balanced with other weapons, and I don't see why that should be any different. The viability of nearly every single weapon in the game is a great aspect of Dark Souls, and unbalancing them in favor of Boss weapons would detract from that.

Also, you have to understand that what's best for PvP isn't necessarily what's best for PvE, and that the game was primarily intended for PvE. The Greatsword of Artorias is an amazing weapon on my SL417 NG+Infinity character! If it were buffed in favor of making it more viable for lower-level PvP builds, then it would become ridiculously OP for my PvE character.

I was mostly talking from a PvE perspective, and it would not necessarily be a steady increase on par with the first +5, but im on NG++ and some of them just don't feel entirely viable. Though my build is rather unfocused and I am currently using the greatsword of artorias (the divine one) and it is great for anything that isn't highly magic resistant. But, some of the unique equipment that only goes to +5 like the boss weapons feels like it could go a lot farther if it could be upgraded farther.

Some of them definitely need to be improved.

The boss weapons are fine the way they are.

My idea is, if you possess a boss soul in your inventory then, the damage would increase but not very high by 50-100 maybe.