I applaud the benchmarking though.
There are still two things that bother me:
1) I don't really know when tilth is called, how it works kind of. Does the model itself select it when it needs it? Do you need to instruct the model to use it?
2) If the model itself chooses to use it, I'd like to have a benchmark of non regressions on tasks where tilth isn't helping, to ensure you made the model + harness + tools as a whole better rather than more specialized ; or be upfront about more specialized and have more details when to use/when to not use.
TLDR; ~3-4% savings to actual API costs with rtk, caveman, and headroom combined, but nothing tangible on if those cost reductions came at a cost of quality. By their calculations, rtk saved them $4.96 on a $926 bill.