That was a mischaracterization of
@readalot's statements. I don't mind arguing a stronger position: You're less likely to get into trouble if you stick to the physiological range of testosterone production, which is about 3-10 mg daily. Accounting for the ester, this is equivalent to using 30-100 mg per week of testosterone cypionate, which in reality is not very limiting. I've been using 4.4 mg of testosterone per day, equivalent to 44 mg T cypionate per week. I have normal SHBG and my daily peak serum testosterone is about 700 ng/L, a far cry from 250-300.
Regarding the original question, some effects of nandrolone are still going to be additive with testosterone, contributing to integrated exposure and increasing risk. While I wouldn't argue that the short term addition of 100 mg/week of nandrolone decanoate is dangerous, if the exposure increases to years then it is a gamble. You have to decide if the benefits are worth the possible risks.