Why can't we sell T4CC?
I know these things are super super super rare and valuable at a certain stage of the game... in fact I just came out of that stage I was there for about 8 months... and maybe it was a security feature to protect people from getting rid of these extremely valuable items..
...but.. once you're out of that stage, when you're in an alliance doing Map 5 5x a week and have been there for at least a few months... then you start to get too much T4CC and usually by then you are also really really craving T4B and T1A (and later T5B and T2A)
So.... why not make it possible to sell these things?
Maybe you could convert them into T4B or T1A catalysts plus a large amount of gold? Or T5B or T2A fragments perhaps? It makes no sense for end game players to be stockpiling hundred of Map 5 crystals out of fear of getting a resource that they can't possibly use or even sell. Currently the Glory store values T4CC at about 10x the worth of one T4B... and the recently closed valor store valued T4CC as approximately 40% more valuable. Would make some sense to be able to exchange the more "valuable" item for one that is supposed to be worth less but at the same time is worth a lot more at a certain stage. Maybe like... sell one T4cc... get... 1 T4b, 1 T1a, and 50,000 gold?
If you don't like the idea of class catalysts being converted into basic or alpha catalysts because they're not of the same type then how about just a bit amount of gold? 500k gold? 100k? 50k? anything would be nice to at least have the option.