Auto line option missing under DSSKey

[Yealink Support]

Hi Barnabas,
Now when you assign all the line keys as line 1 on T46G, when there's second call, the second line key will blink green, so you can know there's second call, and press Answer to answer the second call.
And if you want to switch these two calls, you can press SWAP to switch these calls, the calls which was held will blink green, so you can know which is current call, and which calls were held.
On T28P, even you assign the line key as AUTO, it will also display the same lable of the same account.

So any misunderstanding of this problem? If yes, could you explain to us again?
Thanks.