I suggest MicroStation create an easier way that is direct and simple to edit/modify cells and incorporate a function regarding text mirroring and rotation designed specifically for cells. This also must be a capable functional in both .dgn and .dwg workflow environments.

I would say, duplicate what AutoCAD does as the definition of "direct and simple" when it comes to editing cells. When you are in your AutoCAD drawing and want to modify the block "cell" you created, you just double click on the block, modify what you want, redefine it and close the block with the "save edited reference" all instances update automatically. Editing a “block in place” is very convenient and you can see the “grayed out” entities in the background for your reference. This is one area I think AutoCAD does well in.