Light Touch Regime for member of a couple claiming as a single person

I know the threshold for the Light Touch regime is £338 for a single claimant and £541 for a couple, but what is the threshold for a member of a couple who claims as a single person (for example if the partner has NRPF)?

The legislation is contradictory, as such a person seems to fall within r99(6)(a) and (b) of the UC Regs.

Either way, it appears the earnings of the non-claimant partner should count towards the threshold.

Has anyone had any experience with this?