The cobaya-cosmo-generator does not warn the user and doesn't check the file for inconsistencies. Namely it still allows the user to output, even though no likelihood is specified or selected. Polychord suffers the most, because no default settings are provided as an example, and the end user might not know how to adjust the parameters, or what parameter choices are valid or not. I believe that @lukashergt 's experience may prove valuable here, in designing a set of sane defaults other than