Bloodsaler,
You can reply in Chinese. I read Chinese.
Without see the print copy. It is not easy to analyze the problem.
Only can read all information from your post.
Knowing that materials and consumables are the same for both Mitsubishi and KBA. We can filter these causes.
There are many factors will affect dot gain.
Just name those I know:
1. Rollers and pressure are improperly set
2. Rollers or blankets are too soft
3. Ink is low in viscosity and/or tack
4. Ink color strength is too weak and ink film is too heavy
5. Ink is too receptive to water
6. Blanket are packed improperly or too much pressure exists
7. Ink is pilling
8. Plate is poorly desensitized
9. Dampening system is dirty
10. Fountain solution pH or conductivity is out of balance
11. Sluring or doubling occur in halftone
12. Plate is improperly exposed and developed
From your previous posts, knowing that K and Cyan is very serious and M and Y were close to OK (guess, because I can't download your attachment).
Clause 8, 10, and 12 can be eliminate.
I suppose the M and Y is OK, that means in your KBA, you have 2 color is not OK, I also did not know what is the result OK the ink sequence change, whether the C having improve or remain the same and same as M situation. If after change the ink sequence there is no noticeable change in C and Y dot gain curve. Then clause 1, 2 and 6 also can eliminate.
The clause left would be 3, 4, 5, 7, 9 and 11.
You also mentioned that the ink is the same in Mitsubishi, then we can put clause 4 in the last.
If your KBA don't have sluring and double, clause 11 also can eliminate.
The problem would be caused by ink and water.
For me, the 1st thing I will change would be water.
Hope this can help.