Merry Christmas! And yep, we've been working on getting both preorder/continued-funding stuff set up on backerkit, as well as general add-ons for existing backers. The setup there was a lot more extensive than I had previously planned, but I'm quite pleased with the end result of it. I'll have to explain some of the rationale behind various changes that we made to the addon selection that is available, but basically we found we had some added flexibility financially and structurally, so we decided to take advantage of it to offer more than we previously could.
https://aiwar2.backerkit.com/hosted_preordersPrices are equivalent to the kickstarter goals, minus the "cumulative weight of things prior to them," so it's more of an a la carte setup. This is only possible since we're able to separate out things that contribute to the stretch goals (and by how much), versus how much fulfillment cost there is on the specific item in question. Something we couldn't do during kickstarter itself.
It makes it so that the overall stretch goal funding will be a little more staggered from what it says on that linked page, but that's already true since it doesn't include paypal pledges. So we'll have to have a spreadsheet we run periodically which gives us a total backed via various sources, and then a "total applied toward stretch goals" bit. And then the things that don't apply to stretch goals almost universally add something to the game itself in a smaller fashion (new ark design, new lore, new music track, whatever). The exception being the multiplayer with Keith, but that's a bit of an odd duck of an item.
I'm going to have to do a fuller post about what the rationale is on that page and how it all works, but if there are preliminary questions that you have that might help me craft that post. Mostly we're not going to be emphasizing that page until after the kickstarter fund-collection period is finished (start of January) and we send out the surveys.