So this morning after gambling on engrams for one specific item I was able to upgrade every exotic thing I have and now have 9 spare shards that I won't have any use for going forward. I will only start to collect them as I dismantle duplicate and triplicate exotics and unneeded stuff from engram gambling sessions. I propose that xur be able to convert one shard into 6 motes of light. So if you have enough to buy 4 engrams and don't get what you want you can roll a 5th time for free. This wouldn't break the current exchange rate for strange coins for motes of light and exotic shards. Adding more economic exchange to xur will bring a whole new meaning to the word xurned.