Describe the feature

If you have 50 widgets in storage, autocrafting '64' will make 64 more widgets, leaving you with 114 widgets. This feature would allow you to type '=64' widgets instead, which would only make 14 more widgets, leaving you with 64 total. If widgets could only be crafted in groups of 5, it would craft 15 instead, so that you have at least 64.

Reasons why it should be considered

Often times when I need multiple of the same item in a build, I'll already have a few. If they're expensive or rarely used, overcrafting would be a waste, so I have to remember that I already have 27 of them in stock, and I'll autocraft '55-27' to make sure that I have the exact amount. This feature would make it so that I don't have to remember how many items I have currently, I can just input how many I want with an equals and it'd make sure I have that amount (or more).

Additional details

Not sure what to do if you already have that amount, maybe that should be an error, similar to entering '-1'?