There is already a setting to mix ASCII and tiles, but it only applies to machines (since those were actually designed in ASCII, and the tiles are just a tile-based conversion concept Kacper came up with). You can activate it directly in the cogmind.cfg file via the forceAsciiMachines option.
I could experiment with other options in this regard, sure. It'll just depend on whether the option will cause any rendering slowdown, and there might be some other roadblocks to the logic of it because switching between ASCII and tiles has a few other implications.