There’s already a lot of posts on food/drink portioning, and another handful or so of the crafting-related threads include stuff about reusing cans and bottles (there’s also some on more food types, reworking how stats are given from consumables, cooking, and food rot/preservation).
The main difference between this suggestion and others on portioning is that this is a “slowly hold to consume more at a fixed rate,” while others seem to typically just be a “click to eat one of the portions.” The latter concept alleviates the need to be able to quickly down an entire meal. It might still be interesting to see water consumed at a fixed rate instead though.
Personally, I’d recommend looking at Thing that relate to food (Suggestion) and Item portioning, medical effects, more food. If you just search for “food” in the #unturned-4 board though, you can find a lot of individual posts on food and stuff.