Are there any workarounds for updating records that are not supported by CSV imports? In my situation - WORK ORDER.

Scripting - either directly (all changes with script) or indirectly (import custom records, use those to update the record via script) Workflow - directly make all changes (no csv option here that I can think of) 3rd party solution - for example: Celigo has a free tool for this if you don't already use their services: https://www.celigo.com/products/data-loader-tool/

Mass Updates?