I am sorry but in the four cases I mentioned in my first post, the Cases 1, 2, 4 and the Case 3 had different camera group settings.
When I used the completely same settings except the key point limit and alignment accuracy, the result was:
Case 1. Alignment accuracy "High" and Key point limit 50000: 0.1069 [m]
Case 3. Alignment accuracy "Low" and Key point limit 1000: 0.0247 [m]
Case 4. Alignment accuracy "Low" and Key point limit 3125: 0.0380 [m]
I apologize for the misleading post.
Anyway, the key point limit has a significant effect on SfM accuracy (check point errors).
In the attached Excel file I share the results of all 819 runs so far.
Runs 799, 303, and 783 correspond to the three cases listed above.
In addition, I have uploaded the reports for the three cases here:
https://drive.google.com/file/d/1D9p5wqhFJJxE_WDU1K_g_AvJgA_mp4nL/view?usp=sharing.
The version I used is Metashape Professional Version 1.5.5 build 9097 (64 bit).
Thank you for your attention.