I'm pretty sure it still shows you the mats required even after the GUI pops up, I was printing a few days ago and I was able to see what I needed in the chat box with the title 'SUPPLIES NEEDED'

Contt is correct. The materials list is still sent in chat.

in the old printing system it used to show "supplies needed" and also there used to be a list of supplies missing which was crucial as that was referred to the stuff which is required, the "supplies needed" shows the entire list of supplies req, how would you remember each and every mat which is there in chest or not it is really a time taking process that way, so this new system has only "supplies needed" list, tho GUI looks cool and all but the old system was more user friendly

You're mistaken here - the list only shows the supplies missing now. Try it and see - add more materials to the chests and the amount required will decrease