Cart attributes in packing slip not working

[jplourenco]

Hello, currently I'm adding a cart attribute by having an input with:

     name="attributes[Include Plastic Bases: ]" 

This works well and I can see the attribute being passed to the order in the backend in the Additional details. I can add this to the email notifications, however don't seem to be able to add it to the packing slip anymore..

I have tried multiple syntaxes and I didn't get any luck with the advisor on Shopify support so will open another ticket. All I need is for them to reach out to their dev team and ask someone for a confirmation on this.

Honestly if this is no longer possible it's just disappointing really, can anyone please clarify this? Thank you!!