This in response to ParkerSmithPhoto's question.
To put this in another way, (I'll assume you've used spring supported head/columns before). The head and it's mount to the column are in the same orientation as normal, just the column and baseboard mount are upside down.
The only thing with getting it to work with the column upside down, had to do with the spring that supports the weight of the enlarger head. It originally hooked onto the top of the column, and to work upside down, it needed to hook on to the bottom.
To do this meant removing the "plug" (I don't know what the proper term would be) that fit into the column tube and has a post that fits into the base mount.
Next, I removed with a file, enough material from the backside of the column, where the spring runs, so that the spring hook would sit flush with end of the column.
Then material had to be removed from the back of the plug to accommodate the part of the spring hook that sits inside the tube. And then it all goes back together.
This was a bit involved, but as much as I can, I like any mods I make to things to be reversible so things can still be used again as they were originally intended.
As for the two positions. This is concerning the working surface that the printing easel sits on. Most of the times it's at regular desk height, and here you're printing 4x5 inch prints, up to 11x14's, depending on what kind crops you're making.
But for doing larger prints than this, and I do prints up to 20x24 inches, you can move the surface down to about knee height. This allows me to do almost up to 50% crops even at that size, depending on what format of negative I'm using.