Can I use LATCH (lower anchor connectors) in booster mode, and are there any restrictions?

Graco allows use of the LATCH system in booster mode only if the vehicle manufacturer also allows it, and the child must still be secured with the vehicle lap/shoulder seat belt. If using lower anchor connectors in booster mode, the tether MUST also be used, and the maximum child weight for LATCH in booster mode is 100 lb. For forward-facing harness mode with LATCH, do not use this method for a child weighing more than 45 lb. (Pages 4, 86)