FSH is a 3rd party script. HCS has no part in the development of FSH and as such are not responsible for fixing the FSH code to enable quick drink/wear links with the new backpack interface.
That said, I feel your pain and would like to see them back as well. Perhaps the great guys at HCS may decide to add this feature to the game as part of this "Backpack Improvement" or some other feature that works in a similar way to lessen our reliance on outside scripts.
Once is possible to select many items, they could allow the option "drink/wear/extract/ all selected". It would be easier.