Skyshard Farming Inquiry

I’m trying to get skyshards for the Thundering Ruby Cloud Serpent, I wanted to ask a few questions as most of the info I’m finding either doesn’t answer my questions or the posts are outdated.

I know skyshards have less than 1% drop chance, so I’ll be killing things for a while. But what I want to know is if it’s any different to kill the mobs in old Vale (MoP) or new Vale (BfA). Is there any difference between the two?

I’ve read some things saying that they drop from the treasure boxes and mogu boxes in the ruins, but then again I’ve also found information that they no longer drop from them.

I know killing mobs will be a lot easier in MoP Vale as I can effectively one-shot everything, but I’ve also seen people having more luck in the BfA Vale.

I know people have gone 100’s to 1000’s of kills before getting a shard, but I’m ready for the suffering.

And yes, I do know I can get it from the auction house but I want to work for it.

I got a decent number of shards from the Vale doing invasions during BfA, so you might want to go with that. As to whether there’s a difference compared to MoP Vale, I don’t know.