If you are looking for a certain item, it is because you are seeing that your hero is missing it, just click on it and it will tell you where to find them.
No need, imo, to go to such trouble, nobody will go out from the game to look for these charts to then go back into the game, or however they do it. It is easier to just click on the item, and with some weeks playing you will memorise every location of any useful item.
Also for soulstones, there are not even many good heroes to farm in campaign, and you can see them in-game where they are located also.
Yes, I know that if I am looking for a certain item you can click on that item and see where you can go and farm it, but the problem is, you don't get all the locations of that item, if you want for example to farm for a Shuriken, and if you click the item, it will only show you the Chapter 11 locations to farm it, and there are other locations to do it, like Chapter 12, 14 and 15. It all depends what other items do you need at the moment, so you can choose the best place to do it. And it is impossible to memorize all that.
Yep Don't bother with the Heroic stages, they don't matter much
and I have already memorized the Raid drops (and they are available through reddit), the campaign one will still be useful but the amount of effort it's gonna require is too much.
I have done some research, and I was not able to get the information I wanted from the reddit pages.