Patch notes for v.1.1.7 tell:
Interface
Module upgrade
Module upgrade window now displays loyalty required for upgrade
this is only for modules fitted on the active ship. I suggest to also show the required loyalty vouchers in the arsenal (not sure if this is the correct english term, I play localized, where you can see all the items/modules you own and filter them after tier and mark).
When I filter for green modules and want to upgrade them with vouchers I have to test by right-click and upgrade to see which vouchers are required and if I have enough of them. this is tedious and annoying if done for many items. If i have a green or violet upgrade kit available this is also shown so the vouchers could be shown in a similar manner:
