I have nearly 20 pages of hand written notes on this board over the years. With new discoveries, came more pages, thus it is really hard to follow coherently in retrospect. At first, I could only test ISA grapihcs cards, then with my skyscrapper socket stack, I could only test up to 75 MHz BL3 with VLB. With the BL3 hack, I could then start using 100 MHz, for which I employed the Promise EIDE2300plus and S3 968.
Here are some notes,
16-bit ISA 0 ws vs. 1 ws - saves 17 realtics (when using sound)
16-bit ISA Mem WS at 0 ws - saves 579 realtics (when using sound)
Delay ISA Cycle LDEVJ ws - each CLK2 saves 25-50 realtics, but only with ISA graphics
Remember to set XTOUT=0 in CTCHIP34. This saves 40 realtics.
As for the use cases requiring the reduce wait states, I do not recall. At some point, I get too bothered to keep writing reasons in the notes. It may have been related to adding two VLB cards, or to changing the sound card, or trying to get something working in NT351 for CPUID or HWINFO.
The fact that I'm running the ISA at 8.33 MHz and have reduced other 16-bit ISA properties, could imply some issue with ethernet or sound. However, it could also mean that I did not notice any substantial improvement in benchmarks, thus increased the waits for reasons of conservative. Once I moved the graphics from ISA GD5434 to VLB, the ISA speed and wait-states became less impactful on performance.
Here are some other numbers I uncovered in my notes for DOOM with BL3-100:
Trio64V+ = 26.13 fps
Trio64V+ 0ws BIOS = 26.68 fps
Trio64 w/Diamond BIOS = 26.15 fps
Trio64 w/#9 BIOS = 26.39 fps
ARK1000VL = 26.72 fps
Diamond S3 968 w/Diamond BIOS = 26.41 fps
SPEA S3 968 is a little faster than the Diamond, but I don't have the numbers written down. So either the 26.7 fps value I provided to your previously was the ARK1000VL or was the SPEA S3 968.
Plan your life wisely, you'll be dead before you know it.