Not much has changed in the last several years...
I'm running the latest firmware on a Kobo Aura and I tried a handlful of Arabic fonts (Amri, Mirza, Noto Naskh, Scheherazade) and they range from partially to completely broken in terms of character placement.
Thankfully A_Nefel_Adeti still works pretty well. But I did find two others that work in case anyone's interested: