A company I worked for in Central Africa operated a couple of An2s. A highly-experienced-on-type South African pilot checked out our crew and also emphasised that the aircraft needed to be loaded correctly as it was prone to aft C of G handling issues. I remember clearly painting the bay load restrictions on both sides of the cabin sidewalls to highlight the limits.
I heard that the same pilot was killed at Rand a couple of years later in an An2, along with two others, when insecure freight shifted aft on take-off and it stalled into power lines.