You see, it is all about the SL 1.2 motor. Vado SL 4.0 EQ weighed up to 18 kg (SL 1.1 motor and the 320 Wh battery). As
Specialized decided to release Vado SL 2, the company used a more power hungry SL 1.2 motor, so it decided to compensate the demand with a larger 520 Wh battery. That way, the weight of Vado SL 2 Alloy went up to 20 kg. If you say Como SL 1 weighs 20 kg (chain or belt/IGH?), the upgrade to SL 1.2 and the new battery would put Como SL 2 upwards to 22 kg (at least).
The Como SL 1 IGH review at EBR gives the verified weight of 21.4 kg. Add the pedals and the 2 kg extra and you come close to 24 kg. It is what my first Vado 5.0 2017 weighed!