MaxCut currently does not perform stock or offcuts management.
There are workarounds to achieve something similar to stock management by using Sub Sizes.
Sub Sizes allow a manual import of stock / off cut components. The idea behind sub sizes is your main material sheet can be supplied at certain smaller sizes. Off cuts can be limited to a quantity of product parts so that off cuts being optimised are not more than those available.
To Create a Material that allows sub-sizes
Goto Tools -> Materials -> Sheets
Select the Material
Scroll down just a little bit
You should see Material Sub Panels
Select Add and give the Sub Panel a Maximum Length and Width as well as Quantity
Quantity 0 means it will not be used.
Please note this isn't an automated process but may help you manage usage of stock pieces.