Is it safe to remove SD and sim card while phone is powering on and off?

i noticed someone was removing and putting in the SD and sim card while my phone was powering on and off, and i wanted to know if this is safe or if it can cause issues with the phone? Also they were repairing my phone charging port and said that i encrypted the phone, which i never once did. So i wanted to know if these 2 things were linked or if they could of accidently encrypt it while opening the phone? I'm veryy confused