Never got an alert on this one, and I don't often have much time to spend outside the fish forum, let alone to peruse "reef discussion" :p
To answer the question, those two should be fine together.
For sure.
Agree - sand also defeats the purpose of the fish in/out of the box seeing each other if the fish in the box is buried.
https://www.reef2reef.com/ams/the-acclimation-box-can-this-thing-really-work.16/
Side note, but that 4 line is highly likely to pose an issue with the others in the long run.