I have a Zesto SUT with adjustable ratios and loadings going into a EAT eglo petite also with adjustable gain and loadings for an Aphelion2 cart (and previously a Soundsmith Zephyr MIMC*). In both cases the recommended loadings sounded best to my ears. Differences between settings are extraordinarily subtle to zero, so only major mismatches made a clear difference. In your case, the recommended and available values are very close, so as others have said, don't worry about it.
Question about loading with an SUT
I have a SUT that uses Cinemag 3440AHs. It is set up to have various winding options (thanks Ned Clayton). I am using it with an Apheta 2 and a Denon 103R. The closest winding/loading to spec that I can get with the SUT is a winding ratio of 1:18 with a 150ohm impedance. This is the best sounding setting on the SUT for both carts. I've read that 1:20 with 100ohms is the ideal for the Apheta. For the Denon I've seen some really wild numbers thrown out there but 100ohms seems to be the standard. I'm wondering if there would really be much of a difference if I had an SUT with the exact ratio and loading that is specified rather than "getting close?" It sounds wonderful now and I don't feel that anything is lacking but the devil is whispering in my ear "but what if it could be even better?"