I have latest version of Admin Columns Pro and Admin Columns Pro for WooCommerce
The inline edit features not works (no edit icon shown) on variable products but works fine for simple products, the columns like inline editing SKU, stock, price, customer fields (like MSRP, Cost) only works on simple products.
And I cannot find the “Product Variation Overview” screen show on
That is correct. Not all fields for variable products are inline editable. The reason for this is that some properties are really bound the variations itself, like price, SKU etc. They must be editing on the specific Variation and that’s why we disabled inline edit for those fields.
Since our big WooCommerce update, it is possible to edit these for specific variations on a new variation overview page. The variation overview page is only available when you have at least WooCommerce 3.3 installed. Are you on this version?