Cliff, Thanks for an interesting discussion. A few points regarding your responses.
So jumping from a 240 grit edge to a 3k stone will give you a finish looking like a 3k edge, but a poor one indeed. This is obvious under magnification. You are abrading the peaks of the 240 grit scratch pattern and leaving the depth of the scratches not being removed. The overall look of the edge bevel will look 3k 'ish' but this is not an ideal 3k edge at all. While this is an interesting 'experiment', the conclusion is 'don't do this'. Further compounding this experiment with a leftover heavy burr reduces this 'experiment' to a poorly designed experiment with too many variables to draw useful conclusions. The cutting rate of the stone is also not the critical parameter - it is the duration of abrasion at that grit times the abrasion rate, ie the total amount of metal removed to reduce or eliminate the coarser scratch pattern. The scratch pattern of the bevel is an indication of the actual edge characteristics, compounded by how closely the two sides meet, any damage from burr removal producing fractured and weakened metal, etc. This problem of properly removing the scratch patterns from previous stones is abundantly clear when reviewing kasumi finishes produced by natural stones.
If you are sharpening a Rex121 blade, I don't know that using a stone like a 700 Bester is a useful experiment for bevel setting. Most people on this forum KNOW that this is so suboptimal that they wouldn't do that. For a task like this, diamonds or CBN are a far better solution, especially for determining the primary bevel. This is a particularly abrasion resistant steel (high vanadium carbide content) and cutting this steel with a stone with softer abrasives does little more than wear a stone down, producing an inconsistent bevel angle in the process of dishing the stone. IMHO, this is a pointless exercise. Not really what I would call academic. So for instance, you could hammer in a nail with the handle of a screwdriver, but as you state, "not the stone to do that at all ". In fact, even a collection of stones is not an ideal solution for this type of steel. For most, an ideal approach is of far more interest than demonstrating the results of perseverance with the wrong tool for the job.
Cliff, you are using two definitions of the word 'bias' simultaneously. Biased as in 'I am biased' and when referring to 'edge bias', where you imply that this is a lack of symmetry. Neither use is very useful in redefining the meaning of a burr. And of course these distorted definitions have absolutely nothing to do with any 'academic definition'.
"you say a result it biased as it isn't the true/ideal result if all non-wanted influences were removed. " This is a confused statement.
If you say a true/ideal result [IS, not it] biased because it isn't the true result if non wanted influences are removed' there are some double negatives in this statement. I believe you meant that the true/ideal result is biased because the non-wanted [unwanted] influences are not removed.
What you are describing 'academically' is referred to in statistics as 'covariance'. Again you are distorting the term 'bias' in yet an additional way to confuse the discussion of what a burr is. Uncontrolled covariance due to multiple variables in an experiment is academically referred to as poor experimental design
It makes it MUCH harder to attribute the variable of interest as having a causative relationship.
We should go back to a more basic understanding of what a burr is and avoid introducing 'bias' into the discussion especially with multiple definitions of the word 'bias'. This is simply obfuscating an otherwise straightforward discussion.
So in the first micrograph, there is more than a simple burr present. There is significant edge damage too. Of course not having the burr or edge damage to remove is ideal but this is not the case. Here removal of the damaged edge is best achieved with continued abrasion at the angle you wish to use as your final angle (primary bevel). I am not stating that heavy force need be applied, but rather that the burr and damage be removed in place ('in situ' for the 'academics' LOL) to not exacerbate the edge condition. Approaching this by grinding at a 90 degree angle to the edge does cause unnecessary metal removal. Grinding the edge at a more obtuse angle introduces a microbevel and a microbevel at 2x the angle is overkill. Further, to go back to the original edge angle will now require even more metal removal. A better approach is to GRADUALLY increase the angle until the edge angle is optimized for the required task. Going in the other direction causes unnecessary metal removal. This sort of fine tuning is what makes a knife truly your own.
Finally, to use less water as a technique to refine the scratch pattern is basically clogging up the stone to make it less effective. This is a recipe for glazing the stone and removing the available abrasive for cutting. On a synthetic stone, the abrasive breakdown is minimal, just reducing the total amount of fresh available abrasive resulting in slowed cutting and not an improved finish. While an interesting experiment - with the obvious conclusion of 'don't do this', as you suggest simply using a finer abrasive is the preferred approach. This tactic neither stabilizes the slurry and the term masking is not at all accurate. You are simply causing a clogged stone and reducing the stone's efficiency. You are coating the stone and causing the sharpener to prematurely restore the stone's surface to an optimal working surface using a lapping plate or (less desirable) a 'cleaning stone'. While the topic of optimizing water and slurry densities are worth a thread in itself, running a stone dry to achieve a finer finish is not an approach I recommend.
Cliff, again I thank you for an interesting discussion.