Non-readable +3 or +2 to 3 upgrade tomes should have some turn in options like purified ebb shards (at least, since its an existing system and the new tomes just need to be added to the list of turn-ins)
They are fairly common these days. If I don't need a tome since its BTCoA and I'v already read it, I'd gladly put it for roll if in a party. But from my experience, there have been a lot of occasions where I was soloing (or it was up as an end reward with no other interesting options maybe) and now I have all these tomes just sitting there in the bank eating space.
With the level cap increase, I'm pretty sure we will be seeing a higher number of +3 & +4 tomes drop now. So how about please please please making this change. I don't even care if its not a major difference from +2 tome turn-in, just have some use for them...I really don't see a reason why they are not presently allowed for shard turn in like the lower tomes!