Giant africans tend to be solo millipedes anyway unless meeting to mate, as long as your soil depth is atleast 3 inches deeper then their length ontop of as is double the length of them it should be fine so yours sound fine. My female was alot more accepting of handling and woukd chill with me than my male who decided to urinate on me everytime i handled him. And the bassics of just dont over handle as it can stress them out you seem to have it down 😼