I just picked up the Milwaukee laser measure (for installing LED lights in my shop ceiling), but all of these units look very similar to each other. I found a good website that discusses the accuracy and resolution of these kinds of laser measuring devices. I am including a quote below because I found it useful. So, I believe the Bosch GLM42 is very similar to my Milwaukee in that it has a resolution of 1/32", but its accuracy is quoted as 1/16". However, I think this accuracy is actually linear and would be much smaller than 1/16" on the small scale of making a measurement on top of a table saw. If you look into higher end laser measuring equipment, the accuracy is typically quoted as a percentage, so it is that percentage multiplied times the distance range. Since these low end laser measure devices are typically only a single range like 150 feet, the accuracy is quoted as the total accuracy over that 150 feet. For nice easy numbers, say you are making a cut at 1.5 foot on the table saw, then your accuracy should be 100x better (1/16" divided by 100). That is quite small for accuracy on a table saw!
So, I think the accuracy of one of these units could be quite small (much less than 1/16") and I expect it to be fairly static unless the lighting or temperature fluctuates a lot in your shop. I mean the saw blades light reflectance should be fairly constant over time. If it starts to gum up, it can always be cleaned. It should be possible to make several cuts using this laser measure and use a set of calipers to measure the cut and determine what the accuracy is from this. Once this reading is known, you could simply calibrate your cuts accordingly. However, I don't think accuracy is going to be the limiting factor as it should be very small on the sort of distances measured on a table saw. Resolution is really your limiting factor for making cuts, I think. With a resolution of 1/32", this is the same as the adjustments on the Incra TS-LS fence system, but of course the Incra has a micro adjuster that goes even lower, but 1/32" should be quite acceptable resolution for a lot of saw cuts. Just my 4 cents (it was 2 cents, but I had to adjust for inflation).
https://www.acuitylaser.com/sensor-performance
"The accuracy of a sensor is a measurement of the difference that can be expected between a sensor's reading and the actual distance measured. The resolution is the smallest change in distance that a sensor can detect, and is typically a smaller value than the accuracy error. Accuracy may be affected by temperature, target reflectance or ambient light, which generally will not affect the resolution. "
