Can I use LATCH (Lower Anchor Connectors) for a heavier child in forward-facing mode?

No — do not use the Lower Anchor Connectors (LATCH) when restraining a child who weighs more than 20.4 kg (45 lbs) with the internal harness. For children over 20.4 kg (45 lbs), you must install the child restraint using the vehicle seat belt through the forward-facing belt path instead. Some vehicle manufacturers may also have lower maximum weight ratings for their Lower Anchor Bars, so always consult your vehicle owner's manual. (Page 39)