Lots of 10 hour videos on Youtube, but of course they are loops spliced together, however with Animate you could do much more variety without having to make things seamless loops.
So I tried 4, and it didn't even start.
Two, and it gave the error.
Then one hour didn't work either, but instead of the array message, when it finished it just reloaded the page with no content.
Coincidentally what exports I do get seem to not be very compatible with third party software. The Mp4 export gave the splicer an audio error.
I believe that length will be a limitation as the browser is set to only use 2 gigs of memory.
I also believe exporting one time is easier than several.