Depending on specific account requirements, various options and settings can be changed to improve performance.
Some options that could reduce performance might be set for an account that does not need those options.
allow_book_shipment_before_rating - this options makes the system to NOT rate shipment before booking for parcel carriers.
If Enabled:
The system will rate the shipment after booking in async mode. Item Fulfillment writeback will be made AFTER the shipment is rated in background. So the cost/price in NetSuite will be correct, but there may be an additional delay of the writeback (normally it's done within 1 minute).
IF the customer is using shipping cost/price in their document templates (packing slips, carton labels, mil labels, etc.), the cost/price may be missing or incorrect. Most likely you don't want to enable `allow_book_shipment_before_rating` for customers that need shipping cost there. Consider removing the cost from customer's document template, because the default template includes it but it many be not required for the custoemer use case.
Rating time depends on the number of carriers account has. More carriers - longer request.
Booking time depends on how many Packages/SLIs/OLIs we have in order.
include_packing_slips_into_labels
include_military_label_into_labels
include_ucc_labels_into_labels
Those 3 settings force system to generate documents within the booking request.
For customers that has Auto Print enabled, consider disabling those settings, because the document generation will be requested automatically after booking request.
Number of enabled ShippingPolicies/RatingRules can make the rating and booking slower. Consider disabling rules that are not longer required.
For packing slip templates should NOT contain links to external images (e.g. company logo URL) - that slows down the generation process.