HELP! Plate solving problems

Did you change your Pixel Scale in imaging and platesolve programs after you added 0.7 reducer ?

I have changed the pixel scale and focal length in the SGP profile manager. I'm not sure how to change it in PlateSolve 2.29,
I thought it did it automatically as it is a part of SGP? Can you see anything strange here.

Glad you've gotten it solving things correctly.

As for the slew error, this heavily depends on your equipment. Some mounts don't quite have the accuracy to center to that precision and, although they think they're doing well enough, they end up off by more than your tolerance. They can't gradually inch closer, either, because the mount is probably programmed to enter from a specific side on each axis to prevent gear slop/backlash, which means it will, each time, leave the target and reenter upon centering each time.

The solution here depends on how far off it is. You're saying 200px is being exceeded. By how much and at what pixel scale? If it's 250 each time, or 280 or 300, you should simply increase the tolerance parameter so it stops bothering you. Especially if you're dithering, this shouldn't matter. In my setup it's even less critical; I use off-axis guiding which means I look at phd2 while it's trying to center, and when my planned guide star appears, I stop the centering anyways and move it where I want within the pick-off prism from the phd2 side.

If it's substantially off, say by more than 25% of your field of view, that's another story. For reference, my tolerance has been set to 130px I believe. At 0.35"/px, this is 46" max of error (binned 1x1). If your error in arcseconds isn't much more than this, I wouldn't pull your hair out; just set the tolerance higher.

Plate solving should only occur when you demand it; either because you chose "solve" for the image you took, or because you've set up a "centering" event in the sequence. You can definitely disable plate solving/centering in the settings panel, however I'm surprised that it's off this much. You're using the EQ6R pro? Although I don't have this mount I suspect it should be able to center more accurately than this. Even my AVX would put it within 150 px (after a try or two) at very high focal length (2032mm).

This may require some experimentation to get to the root of the issue, such as trying centering in different parts of the sky (to see if you're getting some weird flexure?) or trying to let it continue trying, and seeing if a pattern emerges. There may be "approach" settings in the mount that need to be improved, or else some other setting being off.

You can definitely center by hand and continue from there. The registration of the light frames will always correct for movement between sub frames. Dithering should be occurring anyways, so every image of mine is off from the previous one slightly.

Mirror shifting also comes to mind, I have the EdgeHD (and have used the 8se) and the mirror definitely moves some, although never enough to throw off centering… But this is interesting since you said it actually gets worse as it continues to center. I would let it go for 5-10 attempts and see if there's something you can glean from the results. It's not unusual to have it be slightly worse from one to the next, since it's essentially just shooting over to the target each time, but if it continues getting worse 10 times in a row without any getting better, this speaks to something changing in your system.