Everything seems to check out fine. Hopefully Toady will have time to push out a D20 so you can get a larger group of testers before it goes into the final merge.
But yeah, it's probably overkill to even think about this. It's mostly just that I'm a perfectionist, and I'm totally out of low-hanging or even high-hanging fruit, so I'm looking for rare fruit growing at the peak of mount olympus.
Your mission should you truly seek the Golden Apple of Calixti: Write a new options screen allowing users to control all graphical items on the fly. They should be able to load different tile sets, adjust the fps caps and display thereof, change between drawing modes, turn on graphical tile usage, adjust the PP count, and change the colors.
If you make it able to save out to the init.txt while still preserving the comments then you will also be given the Sacred Cherry of Cthullu.
Speaking of perfection...
for (int x2=0; x2 < dimx; x2++) {
for (int y2=0; y2 < dimy; y2++, ++off) {
I see someone is using prefix incrementation and someone is still using postfix increments. I grabbed this bit out of the enabler.cpp in the matrix branch but I didn't really dig into much more than that to see if this was called every frame. If you do have loops in the frame it would be more efficient to use prefix operators where order of incrementation doesn't matter (like for loops, single line incrementation...) I know this was the case in C, and I assume C++, but prefix operators do not require the allocation of a temporary return variable to be used by the calling function before incrementation. A prefix operation simply increments the value in memory and returns that value. It's a few less lines of assembly, a few less memory allocations, and a few more ticks of processing performance.
I don't know if your compiler optimizes this, nor have I dug into the assembly of an application to test this, but I read about it a few years back and it totally made sense. I've pretty much integrated it into my regular practice.
(edit: Line 242: frames--; // another example where you would be allocating memory for both the original value and the decremented value... --frames; // should be more efficient)