As written hundreds of time, we must understand very well the difference between these two completely different things: update and upgrade.
An update means you stay in the same version and, indeed, some components are updated. So if you have BH 309, after the update you still have BH309. Only, for instance, BH309A was updated to BH309B.
Updates DOES NOT affect anything of your configuration.
An upgrade is a new install, like when you format a PC and then you install an operative system from scratch. So there is a change of version: if you had OBH 4.1.xxx you install OBH 4.2.xxx.
So, obviously, upgrades imply you loose everything, settings (channels and bouquets) and plugins and their configuration.
You can, then, save at least your settings but you cannot save plugins. I add, that every attempts I made in the past to use the Personal Backups (backup of settings) just to migrate more quickly from a version to another, failed. So I gave up even trying. When I perform an upgrade I simply reinstall everything.
So, don't mistake updates for upgrades or viceversa.