Healing for Emperor Xian

Despite my previous Q&A on the forum.
I am almost 100% convinced that the healing rate is based on the total STA of emperor
The increase in INT for emperor does not help, or if it does -> quite minor

STA from book : 4433
STA from Emperor Volume : 959
STA from Tech + Super Tech: 2100
STA Flag: 1407
STA Jade: 1892

Total STA: 10791
Total Heal: 10981