What to boost Flex w/ citrus solv with?

I did commercial carpet on a 3rd floor with a portable using heated water. The traffic lanes didn't come out too well with the Flex w/Citrus solv.

I let it dwell 10 minutes and then agitated with a CRB before extracting with just hot water. The results are in the pics.

Is there anything I can boost the Flex with to get the patterns out or should I switch to a different chemical?

I do have some Tile Master and Preload on hand, but have no experience boosting with those.