Good you asked this but once you are used to no dig, it will not occur to you even to wonder about it because seeds and plants are fine in the surface compost, from where they root to whatever level they fancy.
Most plants do a lot of rooting close to the surface which is why the notion of ‘incorporating’ compost and manure, to be "at rooting level", makes little sense. Even tree roots can be found almost at surface level and travel an annoyingly long way out, unlike the inaccurate pictures you sometimes see of tree roots in mirror image to trunk and branches.
So your covered beds just need a light raking in any dry winter and spring weather to break up lumps, especially after frost. Then sow and plant at the normal depth.