I would like to suggest making incremental service packs that occurred between major releases available to customers via download links so that customers could do an incremental updates between major releases if it has been a while since they have performed an update. This way it can help reduce the possibility of an issue post service pack installation that server service doesn't start due to coming from an old version. I ran into this issue when i upgraded from 11_2_0 SP-2325_29 to 11_3_0-SP-2400_15 which feel inline with the published direct update path (screenshot attached).