Anyone do Mods to cabover bunk?

That's where my dogs ride. :W

Installed recessed tie downs and attach each crate to them.

All four ride up there safely and out of harms way and love it.
They never get hot because I also installed a reversible 4 speed, thermostatically controlled Tubo Maxxair Fan over the roof vent in the cabover. Stays on rain or shine.

The cabover doesn't really do a whole lot of harm aerodynamically, at least compared to the general shape of the RV as a whole. Making it look pointer would likely not yield as much of an improvement as it looks like it should. (On the other hand, tapering the back end out rather than having it cut off square would probably help more than it might seem it should.)

At least on my class C, the cabover is much more comfortable (and spacious) as a bed than the dinette or jackknife sofa.

Do be careful with storing too much heavy stuff there; often the structure is not super sturdy for heavy things bouncing around as one drives. It's designed to support the mostly static load of people sleeping, but not that multiplied by a few G's for potholes.

Just looking for better utilization of the cabover space, nothing more.

Cutting off the Class C sleeping loft and modifying it to be shorter and more aerodynamic like the Class B is a very tall order. It is something you possibly won't find.

I was referring to poor aerodynamics caused by the cabover. Would like to see DYI converted entertainment centers and storage options.

Storing stuff in the cabover won't cut into mpg unless you've put so much weight into it that it changes the weight distribution.

Some folks convert it to an entertainment center. Most use it for storage.

You could remove the mattress and build a tailgate for it. Then you could store stuff and close the tailgate to keep things in place and hide the clutter.