The Microchip RN4870 module firmware 1.43 (and the Microchip PIC LightBlue Explorer Demo 4.2 DT100112) accepts PauseEncReqPlainText before pairing is complete.
https://www.computer.org/csdl/proceedings/sp/2023/1He7WWuJExG
https://www.computer.org/csdl/proceedings-article/sp/2023/933600a521/1He7Yja1AYM