@milesbeyond
Sounds like an ambitious project!
I thought 999 was the limit, but I just checked and I was able to import over 1000 images into Isadora using the current public release:
Where did you find the 999 as a limit for media files? If you were trying with a different type of file and it stopped you from importing more than 999 into a bin, one thing to test is to fill the default bin with 999 pieces of media, create a second media bin of the same time, then right-click on the new bin and select "Import Media Into Bin.." from the menu and see if the second bin can have 999 more pieces of media imported into it.
If there is a limit of 999 somewhere, a workaround would be to have multiple Isadora files open at the same time, each maxed out on the number of pictures and use Broadcasters and Listeners to control the secondary file + receive video from it.
Example Files: media-limit-workaround.zip
File 1 Example:
File 2 Example:
Best wishes,
Woland