It is possible for SolveToGif to truncate the partially transparent hitboxes if their alpha is too low. It is common that the alpha can be just below 128.
This is a result of gif being limited to 1-bit alpha, but it may be better to at least by default keep hitboxes.
Option 1:
Find a method of defining the threshold value to truncate, and decrease it to maybe 110-120.
Option 2:
Alter the gecko code for hitboxes to increase opacity
It is possible for SolveToGif to truncate the partially transparent hitboxes if their alpha is too low. It is common that the alpha can be just below 128.
This is a result of gif being limited to 1-bit alpha, but it may be better to at least by default keep hitboxes.
Option 1:
Option 2: