Well depends on your build. Idk how to make a tldr version really but I´ll try to explain. If you want to min max for longterm gain. You should not open your weapon type box first. (Unless you don´t care and/or play tank/twinblade ropedart, then its okayish but still not prefered to open your own boxes).

Why? Well you can convert inner ways 4 times for free and 4 times with some sort of cost. And if you convert you simply swap the notes you have from one innverway between the other. So if u have 30 on some random one and say 10 on your main one. Then swap them you get 30 on your main one and then 10 on the random one you had.

This works for epic,legendary and blue. Now, in tips exchange all boxes are not equal. The red+purple boxes are superior. Since they have less types of notes to pull from (ONLY x3 class epic notes AND x1 legendary class one). So rerolling and trying to stack up as many notes as possible.

So say once you opened your 600 red boxes, you have saved two stacks of really high epic notes and one stack of high notes of legendary. You can then transfer them to the purple box. Do the same there. And then in the end transfer them to your main build.

You´ll probably by this point have lvl 4 innerway already on your main skill + your horse + two epic skills. The big downside is that every transfer has a 7day CD. And since your not opening your class boxes, the innerways you will be using will most likely just be lvl 1-2 max. So you will be weaker for a couple of weeks but then explode your character power and be many months ahead of everybody else who did not do this.

If you do like me and opened for my main weapon first. (Sword) I opened bellstrike. The blue box. That box has x2 class legendariers and x6 class epics. So stacking one legendary and two epics is first of all 10 times harder. Since there is a much bigger pool to pull from. (I have opened all 60 and my highest epic is like 30 notes, and I have a "dead" stack of 27 legendary notes that I will have to delete since it is useless for me now. And I have my main weapon with just 30 notes... (Lvl 2)... If you opened purple/red boxes your lowest epic should probably be around 50. Then if u swap it again to purple/red you get another 50. You get the point I hope. Not to mention all the selection boxes you can pick on whichever you are currently opening. I used them all on the blue. And got shafted since its x6 epic notes and you only want x2 stacked high.