A_PBGT_HO = 8 = 4 seconds….
This explains why it takes 3 to 4s to move to the neighbour cell.
However keep in mind that a typical A_PBGT_HO should be between 8 and 12. Otherwise, you will suffer from ping pong HO. Drivetests are very particular, as they don’t represent AT ALL how their subscribers are using their phones. They are mostly static or pedestrian.
Reducing the A_PBGT_HO is valid for highway, or specific micro coverages.