I put all operations in RAMDISK to no write or read on SD card, create a simple bash to execute before MMDVMHost to create a small ramdisk of 120K (or minor)
#!/bin/bash
sudo mkdir -p /ram
sudo mount -t tmpfs -o size=120k tmpfs /ram
sudo touch /ram/mm_voice.sh
sudo chmod 777 /ram/mm_voice.sh
Now Nextion Screen is more complex, all development are made and tested into a Raspberry Pi and use some routines of this hardware. It's possible that only work in Rpi and not in Orange Pi or similar
Are made with DMR only in mind for Hotspots, so only use Timeslot2 and not tested in mixed mode (P25,Dstar,etc) The code made a new screens for Nextion screens.