I think the removal of the stacking-higher-than-normal was a great idea, but with most things there's now a wait time to buy things that don't make a full stack. (i.e diesel barrels - only having 10 in stock at outpost when a stack of barrels is 20) And that's if nobody else is waiting to buy them also.
If there was a way to make it so you could only sell/buy enough to make a stack it might be better.
For example it's currently sell 80 cloth for 10 scrap, and there's only 10 in stock. If it could be changed to stock of 100 then the max stack would be 1,000 scrap meaning no higher-than-normal stack of scrap
300 Low Grade Fuel for 1 diesel barrel, 10 in stock. Change it to 20 in stock and you have a full stack of barrels.
There would still be a wait time for restock, but it would be quicker to sell/buy higher quantities and full stacks.