Hi,
Yes, the anims are too big to store in memory, that is why it is streamed from HDD. (On the positive side the anim doesn't eat up all of your RAM.)
The AMOS code is done by Sövény Imre. You can ask him any question, I am sure he will answer.
The tool is also available on our Itch site: https://electricblacksheep.itch.io/amos-anim-player
There is a ("how to") video on our channel:
If you want to contact us there is an email address we can communicate: electricblacksheepsoftwares@gmail.com