Even 1 pixel border can mess up size requirements, and compensating by adding (prepending) another sides crop action (or even worse editing a previous crop/other) are inconvenient for readability/intent/reproducibility with clear requirements imo.
(And Border action has a clearer intent than simulating with a Canvas_Resize or easier preparation than a dedicated watermark.)

I suggest either (a) a inward=overlay checkbox (b) support negative thickness input to mean inward.
Please and Thanks.