Please note that on March 14th, 2019 Shopify has introduced a limitation to the usable variants number for users to 50,000 (So each individual product will add a count of 1 to the overall number of variants on the shop.) along with a throttle limitation of 1000 variants per 24 hour period, once a shop has reached 50,000 variants.
There is no limit for Shopify Plus users and this limitation is on Shopify's side only, our app has no such limitations.
If you have questions or requests regarding this variant limitation, please contact Shopify support here
If you have questions regarding product uploads and updates, along with choosing the right supplier and Syncee plan for you considering this limitation on Shopify's side, contact our support team here: firstname.lastname@example.org or in our in-app chat.
Thank you for your understanding.