Its not clear to me what your overall goal is, whether you are mimicking your road bike exactly or whether your gravel setup will be done so that the drops will be the main position versus the hoods being the main position on your road bike...?

If its the latter, I would think that you want a higher rising stem to move the main gravel position closer to the main road position. A 5mm stem increase at 7deg is only 0.6mm increase in stack.