As a Type 1 on MDI I was always told not to carb count for veg. If you look through Carbs and Cals many of the amounts are negligible. I think the issue comes with amount of carbs eaten with a meal. So if you have a plate of chips then the peas on the plate will not make a dent in the rise. However, if you are on a very low carb diet then all those carbs will be used in the rise. I found since using a Libre that some of those pesky veg do need extra insulin.
Moving onto pumps, could it be the very slow release of insulin may then need to accommodate all carbs that will also be slow release. As said to you, it will be trial and error.