There were some posts recently on what --full-remote-verification actually does, and the documentation says it looks deeper, opening up the files instead of just checking hashes. It’s not a replacement for high test samples. Samples, by the way, also accepts all or everything, if you don’t want to make up your own very-high value.
Discussion is in several posts around Backup issues following NAS crash - Hash mismatch and I just tested too, using samples of 1 along with --full-remote-verification. I got only one sample-set downloaded, watching the log.