I don't think that's a fair assessment. It was drawing on the same worldbuilding, but it was another story about the Klingon court/penal system, so naturally there were some recurring ideas. The actual story it told was quite distinct. Maybe it did go a bit overboard on the TUC homage, but "ripped off" is an overstatement. Now, that's really pushing it. The only thing they have in common is that they're both set on Risa, which had become an established, recurring setting in Trek by the time ENT came along. Now, that's the one example you've offered that's actually valid.