One Gallon "Off the Topper Kit"?

I see that this kit is available as the included beer kit if you buy a new One Gallon Starter Kit, but I don’t see it listed for sale simply as a kit for those of us who already have a One Gallon Small Batch Kit. Am I missing it somewhere on the website or is it really only available in the 1 gallon kit with a new full starter kit?

I don’t see it listed under the 1 gallon kits either.

Might be worth it to ask NB if they can sell it separate?

The plinian legacy 1 gallon kit is only available with purchase of a starter kit as well.