I think the reasons why my caimito wasn't healthy was mainly due to soil conditions.
I live on limestone heavy soil and Caimito likes it more acidic.
1. What I did was pulled back some of the top soil (being gentle to not disturb the surface roots)
2. Replace it with peat moss
3. Added sand on top of the peat moss (my logic was to try to direct water into the peat moss)
4. Throw a good bit of sulfur, 2-3 cups. (i only had micronized sulfur at the time)
5. Covered it all up with a thick layer of mulch.
The result were night and day.
Scale just seemed to attach whenever but will a healthier tree it rebounds faster.