Is it okay for us to update to 5.13.x?
It says...
"TL;DR: Stay away from FW >= 5.12.x" [0].
"If you do decide to go with a more current FW version, *avoid* anything >= 5.12.x, as it has become even more aggressive, preventing you both from blocking OTA updates, and greatly (potentially fatally) hampering the JailBreak's ability to survive, as well as your recovery options" [0].
[0]: Open Sesame,
https://www.mobileread.com/forums/sh...d.php?t=320564