Help with LTL not infinitely splitting our shipments to new warehouses…

We (US Seller) are trying to send several smaller skus to Amazon for FBA via LTL, in total about a pallet worth of product but we could send it in 2-3 pallets if needed, that is fine. Every time we add a new product and try to merge with the existing LTL shipment it allows it but invariably they throw the new product into a new pallet that is way under the 150 pound limit and once we merge the LTL shipment there is no way to un-merge it. The more product we add the more pallets to different warehouses they make us use, but now several of them are UNDER the 150 pound rule.

We would love to just pull those out and UPS those small items rather than putting them on all new pallets but of course that isn’t an option. Constantly having to cancel the entire shipment and start over from nothing and try again. Anyone have any advice on how to navigate this?