Hello. Found how to speed up the movement.
Disable the setting "When changing the balance of goods in the warehouse, recalculate prices for it"
https://crm.kidzaza.com.ua/admin/shop/settings/recalculate-price/ . Instead, set an hourly action to recalculate prices and availability (running only a few times a day) if you need it. As far as I can see, you already have it and perform the necessary functions.
Difference of movements from the specified file:
With checked box - 30 seconds
With the checkbox off - 4 seconds
Why so long in the included? You have 400 products in the file, each product calls for a price recalculation, which climbs into markups (recalculation rules), then into suppliers, processes a bunch of data, calculates the price for each supplier for each markup, selects the most profitable one, puts down the price, availability and saves the product. After saving the product, product automation actions are also called, which additionally climb into the product's additional fields and do something else. Accordingly, there are a lot of actions and this results in 30 seconds of load.
Without this checkbox, your box will easily move about 100 products in 1 second, 400 products in 4, respectively. I think that this speed should suit you perfectly.