Would you recommend off-label use of nedosiran for patients with primary hyperoxaluria type 2?  

For a couple of reasons, no. The evidence is not clear if it works or not for PH2. If there is an effect, it is probably quite a bit less effective on average than for PH1. The cost is extremely high for a trial of something we are not confident will help. It is not FDA-approved for PH2, thus, ...