Haven't heard anything about "re-education." Just stories about starvation, torture, losing so much weight they look like holocaust survivors, etc. And these guys recover and go right back to fighting. Those documents are at best worthless since killing POWs is still a war crime and Russia is well known for doing it anyway. And at worst a problem for whoever made them sign them, since it just means these guys will be even more motivated to fight and not give up.
Chechens fled or surrendered in large numbers in Kursk region. They're nicknamed the TikTok army.
Been following Ukraine since 1979.