Hello HashibaHayashi,
Thank you for getting in touch with us! Here are some answers to your questions:
1. YEP series should be above the CGC plugins. We should be compatible with most of the Core ones like Core Engine, Battle Engine Core, Buffs States Core etc.
2. Battle Engine Core should work once you have placed it above the CGC plugins. DTB and STB systems work best with CGC. We don't currently support ATB and CTB systems but may in the future. Also Action Sequences work along with CGC Notetags but the order of execution may be worth testing in your project.
3. Help Box Control checks if State Info Popup exists in the Plugin List as a dependency before it makes the changes based on the State Info Popup parameters. If you got it working the other way around that's probably fine, but at least on our end it only works when you place those above. We can edit the help file to include your case.
We'll take all the blessings we can get! Let us know if you run into any other issues and we can help troubleshoot.
Thanks again,
MythAtelier Team