The Layer Index provides a list of available distros, but Toaster does not take advantage of that information. The proposal is to: (a) Add a selection box with lookahead, just like the MACHINE selection. (b) Add a selection Toaster Table, again like the MACHINE selection. (c) Leave the existing manual edit in the configure variables page, in case the user wants to set a distro not currently published in the Index. I have a working implementation which I plan to contribute to Toaster.
commit 4f2baebf362d71351db044c0646f9bc6e8a39c49