I dont use CEC myself, never liked it and as i have a logitech remote its not needed at all.
Some Nucs that dont have IR or wake possibillities i simply use an old Flirc dongle or even a usb keyboard. wake from powered off works np.
I did buy a new tv and for some reason it doesnt report HDR signal when playing from Libreelec. If i play something from my AppleTV is instantly shows HDR/DV or whatever format is used. Need to investigare this.