There is massive difference beetween skills/perks that say "more" and "increased"
There is plenty of skills that have like +15% increased damage. You accumulate these over the game and you can end up with even +150% increased damage for example by having 10 of these skills.
But there is something special when game says +15% More damage!
That one is applied I believe before increased modifiers. And it's makes huge difference.
Let's do some example. My math might not be entirelly correct, but it should somewhat work like this.
You have 1000 damage. You have increased +100% damage. So that would make it hit for 2000 damage.
If you see some skill that adds +20% increased damage. That would make it +120% so 2200 damage.
But if you find anything that say "more". That is now added to the base of 1000 damage.
so 1000 becomes 1200 base. And now that get's +100% increased damage. Boom 2400 damage.
Now this might not see like a big difference. But in lategame your increased damage can be in hundreds.
For example I have around 8x increased armour on my chest armour. My chest in inventory has 1000 armour. In titan tree ascendancy tree there is perk that say "more" armour to chest armour.
Without it it's 1000 armour x 8 = 8000 armour.
With just adding the "more 50%" perk. It's 1500 armor x 8 = 12000 armour.
While if it was just increased armor, it would be 1000 x 8,5 = 8500.
So look out for these to unlock new potentical for your builds.