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Making query for every line item is not recommended. It will probably cause no harm for very low numbers of line items, however it is not a recommended practice.
Querying Price
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Across Multiple LPGs
If the sku SKU can be present in multiple LPGs, you will most probably need to make a single query accross across many/all LPGs. This will be possible only if you allocate the attributes to the same elements. See how you can configure these mappings: https://pricefx.atlassian.net/wiki/spaces/UNITY/pages/4611671141/Defaults+for+Price+Lists+and+LPGs#Preferred-Field-Mappings
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