You miss the point, it is very similar problem as the EDS, also it is similarly divided between hardware and software.
No, I do not miss the point at all. I've already agreed with you on this issue as I stated here previously:
OK, with that out of the way, let's proceed with the promised discussion regarding SG's comments on the factors contributing towards dead time effects in WDS spectrometers, because there is no doubt that several factors are involved in these dead time effects, both in the detector itself and the electronics.
I've actually mentioned several times previously that there are several separate effects are involved in the WDS dead time correction, so please stop with the "straw man" arguments.

Here's another example that just popped into my head: have we thought about satellite line production at high beam currents that could rob us of counts on the main emission line due to double and triple atomic ionizations in our sample? This effect (if significant) is of course only a problem in WDS because of its high energy resolution, and can *only* be corrected in software because the photons don't even ever reach the WDS detector!

But the more important point is that from what we see in the constant k-ratio data, we can make software corrections for photon coincidence quite easily as you yourself have already acknowledged:
However, I think probeman's et al model is too little physically realistic as it accounts for pulse pile up's too weakly (not to strongly as Brian's argumentation suggests) and that gets obvious at higher currents/higher count rates (I don't see that high count rates as anomaly, but as one from pivotal points in testing the correctness of the model). But classical "linear" model does not do that at all, so in that sense this new log function is much better as it do it at least partially, and while it is still not perfect, it is a movement in the right direction.
You're welcome!

I can live with "not perfect"!

So, with this new log expression we have enabled WDS quantitative analysis at count rates up to 10 times greater than what was previously possible. But above that we run into the more electronics dependent limitations as I stated here previously:
But however we measure these dead time effects by counting photons, they are all combined in our measurements, so the difficulty is in separating out these effects. But the good news is that these various effects may not all occur in the same count rate regimes.
For example, we now know from Monte Carlo modeling that at even relatively low count rates, that multiple photon coincidence events are already starting to occur. As seen in the above plot starting around 30 to 40 nA (>50K to 100K cps), on some large area Bragg crystals.
As the data reveals, the traditional dead time expression does not properly deal with these events, so that is the rationale for the multiple term expressions and finally the new logarithmic expression. So by using this new log expression we are able to achieve normal quantitative accuracy up to count rates of 300K to 400K cps (up to 140 nA in the first plot). That's approximately 10 times the count rates that we would normally limit ourselves to for quantitative work!
So, yes, this log expression produces *only* a 10 fold improvement in quantitative analysis at high beam currents!

But if you ever do come up with an paramatizable expression that can correct for these WDS electronics limitations at count rates over 400K cps (for JEOL) or 300K cps (for Cameca) please let us know and maybe we can implement them as a separate correction, in addition to the normal dead time (photon coincidence) correction. You can name it whatever you want!

The problem I see is that there may be significant differences is how these electronic issues should be treated on JEOL vs. Cameca hardware. But maybe there is enough similarity, though the Cameca "enforced" dead time would seem to be one difference between them.
JEOL here has the advantage because JEOL instruments have intrinsic dead times about half of Cameca's, so clearly this is more important for Cameca instruments, but certainly could help on all instruments.
The SDDs are fast because they have a much better signal P/B ratio, which made it the much smaller shaping times (like 25ns and even less
) practical, while manufactorers of WDS had not updated its counting design practically from 80es (there is only replacement of some counting component chips with equivalent modern counter parts). That is how EDS can cope with 8Mcps (at least on the paper: newest AMPTEK SDD systems) input count rates with "extendable" deadtime and practically with no PHA (energy) shifting, while our WDS counting can't cope with not-extendable deadtime and experience severe PHA shifting already at 150kcps. Software can do some corrections, but it is a bit uphill battle.
I could not agree more with you on this point. It's simply criminal that WDS is still relying on 1980s electronic technology! I'm just doing what can be done in software because that is the only area I have any influence on.
But again, if you come up with a software correction for these WDS electronics limitations I would be very happy to test them out.