it is probably fine and your tweaked results looks fine for average DX4.

The cachechk is complaining as there is only a small difference between L2 and RAM is small (26 vs 28 μs), but there is still some.

Your RAM is probably as fast as it gets. Depending on your motherboard and SRAM chips, you might be able to tweak your L2 cache speeds which would increase the difference. My tuned boards usually gets to about 20μs or 55 MB/s with DX4-100.

AMD 5x86 133 - What make/model is your motherboard? Might be hard to install if it doesn't support 3.3v CPUs and probably won't be much faster than a dx4 overdrive unless your Motherboard/BIOS supports the L1 cache in write back mode. If the answer is "no" to either of those, your best bet for any noticeable performance increase is a 83MHz Pentium Overdrive (or get a different motherboard, which might be cheaper)

VLB IO/IDE Controller Can improve disk IO if your OS supports 32bit DMA. So that means running under windows with IDE DMA turned on or finding some DOS UDMA drivers that work with your board.

Extra 1mb on the S3 card Fun to do, but has no measurable effect on performance. Might give you better 2 d color depth since the Trio has a 135?MHZ RAMDAC.

maybe more L2 tweaks could help maybe, but don't expect performance improvements that are clearly visible outside of synthetic benchmarks.