I thought I would chime in,
I have been using the kstars beta 376 and tested last night, I was running a series of ten minute subs. and guiding for couple of hours, the sky did have some high very thin cloud waft through.
I was getting some oscillation with the dec axis, and I am not sure what caused it
My polar align is fairly good and scope balanced well
NEQ6 celestron edge800, OAG using qhy 178 guide camera
Stellarmate version 1.5.9, Kstars 3.5.5 (376 build) on windows pc. Ohhh also agression on RA was better at .9 too, I did try changing the dec, but did not see much effect. GPG was also engaged.
I have included both the Analyse and a phd logveiwer snap of results.
The guiding by the numbers looked great, but is that understanding what is the oscillation  caused by?
I thought I would chime in,
I have been using the kstars beta 376 and tested last night, I was running a series of ten minute subs. and guiding for couple of hours, the sky did have some high very thin cloud waft through.
I was getting some oscillation with the dec axis, and I am not sure what caused it
My polar align is fairly good and scope balanced well
NEQ6 celestron edge800, OAG using qhy 178 guide camera
Stellarmate version 1.5.9, Kstars 3.5.5 (376 build) on windows pc. Ohhh also agression on RA was better at .9 too, I did try changing the dec, but did not see much effect. GPG was also engaged.
I have included both the Analyse and a phd logveiwer snap of results.
The guiding by the numbers looked great, but is that understanding what is the oscillation  caused by?

  
 

Hmm, oscillations usually point at overcorrections - but that is clearly not the case. Rather backlash. Have you measured that?
What intrigues me most is that the errors in RA and DEC seem phase shifted, which could point at a crosstalk. How does the calibration look? Are the axes perpendicular?

Here is the cal from the session, PS the mount fully adjusted and has Rowan belt mod.
 

Here is a bigger view across most of period. 2 sets just after 2050 and 2150 where oscillation happened signifigantly

(a) I think Pit's intuition about being too aggressive is probably right, but
(b) I wouldn't touch a thing if you have 0.24 RMS with an NEQ6.
Hy

Next night when no clouds I will start off with low agression on dec and ra, and see how it goes. I would prefer lowest possible, but need a good amount of time to test all settings to see what results
Ohh PS I only upped the agression after an earlier oscillation, which seemed to bring it down, but the session on pics show afterwards, but lost the sky to clouds.

Not sure - I'd definitely increase the number of points for the calibration, it somehow looks suspicious to me.

Hy - is the calibration somewhere measuring/reporting backlash? I don't think it's aggressiveness. There are always multiple (many!) pulses before the drift is caught. Too high aggressiveness would be an immediate overshoot after the pulse. Either backlash, or too low speed from calibration..
Or a mismatch in pixel size?
Clive, is this the very latest build from Hy, with the binning correction?

It is build 876 from 7sept  Kstars nightly build
Mount backlash is fairly tight, zero movement, with rowan kit too
2086 FL dirived from platesolve, so should be accurate

Pit,
Calibration never prints out the backlash, but it is measuring x,y points while it turns around DEC. One could see all those measurements in the log. What calculation exactly would you recommend? Do you need to turn DEC around many times?
Hy

My "binning change" went in on Sept 8, 10am California time, so Clive, you probably don't have that fix in your binary, but that fix wouldn't affect you unless you had calibrated with one binning, but were guiding with a different binning.
 

I was just thinking of the 'remove backlash' option, assuming that one does small moves until the guide star actually does move - then this duration/distance could be reported.  Not sure if some extra routines would be needed though - if one wants that, might be easier to use PHD2?

As for the guiding:  I just compiled the latest git (which seems to be identical to your guider-fix13).  I re-ran the guider calibration (equator near meridian), which gave me the (almost) exact same values I had before (angles within half a degree, speed 1.5ms/").  The attached image shows the EKOS tab.  Guiding as usual
I calibrated at binning 1x1, then for a test switched to 2x2.  No change in the arcsec display here, RMS around 0.25" , like with 1x1 binning.

Cheers,

  Pit
 

Best place to do a calculation on DEC backlash is to do it during calibration when the DEC goes from DEC OUT to DEC IN. The difference between those two would give you the backlash value you would need to take it out, if your mount had that capability.