Archibald's rig looks great! Totally portable. My thoughts about the lightbox were not aimed at nature shots, obviously, but rather more technical macro shots.
BTW in-camera focus stacking is really neat. I'm not sure when Canon started adding it as a feature but the R3 and R7 have it. I haven't tried but I believe it will work with some Canon flashes, too. I know I can get 10~15 fps out of my 430EXii at low power.
For Canon, flash (Speedlite EL-1) only can work in focus stacking mode with R3 and other models don't allow flash under this mode.
The focus stacking mode in Canon is a great feature since it provides in-camera depth composite jpg photos. If it fails, we could repeat the process immediately. Moreover, the speed for stacking is very fast and sometimes better than the stacked photo using Digital Photo Professional.
I have been using it many times, you can find my photos in the Macro Shooter forum
Although the in-camera focus stacking mode does not allow the use of flash, it has fast FPS, sometimes it is more important, especially on windy days and when small insects hanging on a thin grass stem.
Uncropped image, handheld in-camera focus stacking (10 shots CRaw), natural light. Post-processed with DPP and Denoise AI
The image is not very clear as a relatively slow shutter speed was used (1/125s)
In-camera jpg photo generated from focus stacking (focus bracketing/depth composite enabled), uncropped unedited photo.