My idea is that DHS can publish a data on website or an mobile app which lists of countries allowed to enter USA and which visas are allowed to enter the USA.This will help any Business or Work travellers plan ahead to avoid confusion at the port of entry.
Country Entry allowed for visas Entry not allowed
UK L1/H1/B1/F1 B2/J1 etc
India L1/H1/B1 B2/J1
Brazil L1 H1/J1/B1/B2