Just did my first time exit at Kunming (guy seemed really surprised I wouldn't listen to him and go get in line for manual processing), but photo and fingerprint both worked fine. Then return was at Guangzhou -- same thing although there was someone checking all Chinese passports before letting them go to the e-Channel side. I said "I'm registered 我有申请” and he let me pass without even scrutiny of my passport like he was doing to Chinese citizen's passports.

My fingerprints seem good -- I never have ever had to place my four fingers again on the normal print reader.