Not sure how closely phenaz0l@m compares to phenazep@m, but caution is required for any strong benz0 that has a long onset time and long duration. As someone already mentioned, there used to be a ton of stories of people losing their jobs, crashing their cars, and waking up in a cell after a prolonged blackout.
I believe many (most?) of those cases came from using a p0wder form. They took some and waited 30 minutes, didn't feel anything, took more, and before they knew it - lights out.
I think this has all been mentioned already in this thread, but it's worth repeating. Stay safe.
I researched it years back (right around when all the horror stories were coming out) in p0wder form but was extremely cautious and never had issues.