QuickSANE was described by its creators (back of archived brochure) as, “A control panel device (CDEV) that acts as a "traffic manager" routing SANE (Standard Apple Numeric Environment) calls directly to the MC68881/2 coprocessor. The result is that math-intensive operations are executed up to 300% faster once QuickSANE is installed. For Macintosh II, IIx, Ilex, Ilci, and SE/30.” Evidently such calls don’t happen automatically, else why would the software have been written?
What all this means in actual use is, of course, another matter, but hey, that guy’s SE/30 (linked) was nearly twice as fast in cpu scores in Speedometer.
I don't see the link you're referring to, but I can speak authoritatively to this: The CPU score shown under "Performance Test" is purely testing integer performance and
will not be changed by SANE patches or presence of an optional FPU.
The "benchmark mix" score is normally an integer performance test also. However, some of the patches performed by DayStar/Diimo's tools (can't speak for QuickSANE) will have a dramatic effect on KWhetstone subtest's score. So that one test is doing something that is using SANE.
Otherwise SANE patches have very little effect on any of the other benchmark mix subtests, however the average score will be artifically inflated due to the manyfold performance increase
in that single subtest. It would be interesting to understand what SANE calls are being patched and also if the IIsi ROM with the newer SANE package exhibits the same speedup. Either way, this is not representative of a general speedup of the machine.
IIx/IIcx/II/SE/30 all essentially use the same ROM and yes, SANE in those ROMs will not utilize the FPU. So SANE patches are of use on these machines (
so long as the stock ROM is installed). The IIci in the QuickSANE list is an outlier as that ROM should be extremely similar to the IIsi ROM, I would be surprised if it lacks the improved FPU SANE package. The IIci developer note does not mention any ROM changes, but the IIci ROM is one of (if not) the first Universal ROM and the IIsi is very closely related both hardware and ROM-wise.
Regarding the topic, the LC2 aka Classic II aka Color Classic are all architecturally identical and all use a ROM that is
newer than the IIci/IIsi ROM. Therefore, it will have the FPU SANE in ROM and as
@Arbee said will utilize the FPU if it is present. So there is likely little or no point to installing a SANE patch, but you'd have to find something that specifically tests SANE routines in order to confirm that.
Text rendering doesn't utilize floating point operations / SANE to any notable degree and won't be helped by a FPU. Again, SANE is mainly concerned with floating point operations which are by necessity minimized for performance considerations as early Macs did not have a FPU. Scrolling is purely a bandwidth constrained operation and will not be improved by a FPU or SANE either. Unfortunately as I mentioned previously there is not really a benefit to having a FPU outside of the rare and usually niche applications which leverage a FPU, even with FPU SANE in ROM or SANE patches installed. The FPU will not make the machine any faster in general use.