I've seen segwit transactions as both version 1 and version 2.  When should version 2 be used versus version 1?

Example version 2 tx:  c586389e5e4b3acb9d6c8be1c19ae8ab2795397633176f5a6442a261bbdefc3a

Example version 1 tx:  4ffb6404517ad30869f125b7f2f23a9058313d736a72a996b1381f1fe6f04e07

Both are in blocks on mainnet.