Running a stocktake on a large catalog used to mean the CSV upload or download could time out before it finished. Both now run as background jobs, so the file size of your catalog is no longer a practical limit.
On import, quantities and cost changes are collected and applied together as a single authorized adjustment once the whole file is read. Other field updates, including buffer quantities, min/max levels, barcodes, bin locations, and supplier SKUs, apply as the file is processed line by line. On export, the file is prepared in the background and ready to download when it is done. Progress and completion appear in the in-app activity feed, so you can keep working while it runs.