Have it so in the ./shop ingame with blocks and items you can have more options for buying increments of items instead of being able to minimally buy 1 stack or having to buy 1 stack at a time. The incremements should be customizeable being able to add, remove, etc. eg. Buy 64, add 1, remove 1, add 10, remove 10,. I personally think having an option to fill up every availble slot in your inventory with said item you are trying to buy would be amazing to have saving clicking time.
I generally like this idea and have thought about it a lot, i also have created a mock up version; however, this simply has been delayed due to much work being done to create a stable version of Peaceful Farms on 1.14, please notice if this isn't released with 1.14, it'll be released soon after.