Ali Reviews can help you to import maximum 10000 reviews for each product depend on the plan you're in:
Premium Plan: 10,000 reviews / product
Essential Plan: 1,500 reviews / product
Starter Plan: 500 reviews / product
The quantity of the reviews depends on your needs. However, the number and size of images attached to the reviews may slow down your web speed if you get too many reviews for each product.
Hence we highly recommend you to add from 100-200 reviews for a product to speed up site load, and avoid overwhelming customer with reviews.
If you need some more helps, please feel free to contact us via live chat or email us at firstname.lastname@example.org