Stockable variants plugin and product cart amount update

[p.barg]

Hello,
using the stockable variants plugin I noticed that the product amount in the cart doesn't update if the same variant is ordered multiple times.
Instead the same products are listed as separate items in the mini cart and cart (and also all documents) which looks rather odd and misleading.
The problem doesn't occur if you use Generic Child variant instead of the plug-in.

VM2.6.6

Petra