Reading through your other posts it seems like weights are more complicated for you. I am going to think on this more! We ship with a service that doesn't require a weight to be specified so I haven't learned shipstation's tools in this area.
No, because adding an ounce changes the postage by a different amount depending on the package or method.
I want "always add ten cents, irrespective of anything else."
Also, adding an ounce to the weight is a manual process as well as simply being wrong. I'd like accurate weight. I just want an extra dime purchased.
I deal mostly with shipments under 1lb and do not have the concerns you do. I do not get things rejected for being overweight, and I know I push the limit sometimes. Big to me was knowing where USPS did their jumps in price. For me, items only go out under 4 different weights...4oz/8oz/12oz/15oz.