https://play.google.com/store/apps/details?id=co.easy4u.ncleaner

As I said before, LG V20 is last Flagship Phone with a removable battery, due to that feature not being profitable for phone manufacturers.....While I won't go as far as you, and call any phone without a removable battery a Brick...I do understand your issue..

Not sure why ignoring updates, is such a big deal for you; I've been doing it for years, with no problem.  Whenever I see the popup notification for a software update: I simply ignore it.  But if that doesn't work for you, you can go to the Google Playstore and download "Notification Blocker".  This app will block any notification you choose, from poping up on your phone .....See attached Link Above..