That's fascinating to find out! I grew up a fan of Nova Logic, so I'll have to pay attention to this the next time I revisit their games.
Was this done for Comanche or did you also do this for Delta Force?
I did the first version of the matchmaking for the network play in Delta Force but didn't make it into the credits because I quit before it shipped. My psycho coworker built a custom web browser(!) that integrated directly with my from-scratch matchmaking server. At least they let me work in C for that project; most everything else I had to do for them was assembler because that was not a "sissy" programming language. That server code was by-far the coolest thing I wrote for many years afterward.
Unfortunately, my server code couldn't handle more than like 32 concurrents because the Windows NT 3.0 kernel would BSOD with more. My (extremely grumpy) manager and the Sega Saturn coder called me a few days after I had quit to ask how the code worked. I suspect I left data in the socket buffers too long (was trying to batch up my message broadcasting work at regular intervals) and the kernel panicked over that.
I recall learning later the TCP/IP stack was homegrown in NT by Microsoft at that time and they licensed a good one for later versions, so I can't be blamed, it wasn't me! :D
The reason facing east-west (or was it north-south, now I'm unsure) made such a difference in framerate was the color and height maps were ray marched in straight lines up from the bottom of the screen to the horizon. This meant you were zipping through the color map in straight lines, wrapping around to the other side if the ray went far enough.
When those straight lines lined up with the color and height map (north-south), life was good (and when a ray marched up a sheer canyon wall, life was VERY good.) But, when those straight lines went perpendicular (east-west) to the color and height map, you were blowing through the L2 cache constantly and going to main memory very often. I imagine on modern hardware these cache misses wouldn't amount to much measurable time, but on a 386dx with 8megs of RAM, the impact was very clear.
Novalogic was the only programming job I ever had where I got my own office with a door. ;) When I was with them, they had a policy of one game developer per game which I never saw again. Maximum cowboy coder energy, good times.