I don’t like the Updater app, because it creates a confusing userdata folder on the storage (which in fact is a mistake), and I had bad experiences in the past with my former Nexus 4 storage being wiped out accidentaly via MTP for that reason.
But anyway, I need to have a computer near when I update, because I patch the system with Needle/Tingle for faking signatures, which is needed by microG to impersonate Google Mobile Services.
Besides, I change emojis to the EmojiOne set, increment DPI settings (add ro.sf.lcd_density=430 to build.prop, instead of 480) and apply AdAway adblocker, and I like to make a backup of system and store it on my computer in case anything crash and I need a quick restore.
Yes, I have a complex update procedure, I have to automate this process sometime.