You are right! I just tried it my self – and it does revert to 1000 indeed.
It is NOT a limitation of your computer (which is more than capable!) and not a limitation of Animation Paper in reality – just a number-limit we must have put in for some reason in the early development days. 🙂
I must have imagined that you did not want to ever start with more than that many frames, since its better to add them as you go along. But I guess we didn’t anticipate the way we made audio work. So you are right, we need to set the limit higher.
For Alpha 4 we will increase it to 10.000 frames. Thanks for making me aware of this funny arbitrary limit!
But what you do right now (with your current alpha version) to get to 4000 frames I don’t see a super obvious solution to I’m afraid. Fastest way to get to 4000 is to do your initial 1000 and then just hold your ‘ key (shortcut for Add Clone Drawing) for as long as it takes to add all of them.
I do not recommend trying to copy and paste 4 times after selecting all 1000. Just tried it, and it will take for ever. For some reason AP seems to be quite slow when copying just clones, that potentially aught to be very fast, like when simply adding them. Anyway, one more thing for me to look into. Thank you!