[Elecraft] Main Menu--ATTEN function

I recently was setting up my K-3 for interface with WSJT-X software. In checking to be sure that the sound card was connected to Line-In, I found this menu setting. It appears to be a new item from a firmware upgrade, as it is not shown in my users manual. It is positioned between ALARM and LCD

[Elecraft] kpa1500?

As a 6 month Elecrafter (k3+p3) I have never seen any discussion nor requests for a legal limit compatible Elecraft amplifier with the seamless attributes of the kpa500 . It would seem that the now extablished 1000 w devices could form the basis for a commercially viable amplifier. Perhaps no