TheCoder1998, this and similar questions have been answered in depth, thoroughly, in different ways by different people, all throughout the forum, from the time it began and it will until quantum computers are invented (in which case, we can pretty much do whatever we want.)

I'm going to try to be brief and understandable.
There are 2 reasons in this community things don't get done generally, in the software area for projects like this.
1.) Programmer is either incapable of the request or the device is incapable of supporting it.
In this case, the calc does not support a legit savestate feature that can allow for saves to be transferred as individual files between calcs. The closest you get is the unique system with which his application can and does store environment variables and all of the game's memory in appvars/in SMC in the ROM itself. It IS possible to save your state, otherwise my time spent using the application would have been miniscule. I don't knwo exactly how the process worked, but you can load the previous state of the ROM into the game via some process I used to have to do over and over. It also helped when the game crashed or I ran out of batteries.
2.) The programmer has no interest in completeing the task.
Programmer will either lose interest, not care enough about userbase, not place much value on whatever you want to have implemented, feels insulted (as in, feels like the userbase is just USING him instead of appreciating his incredible feats in coding and hacking), have no time to do this, no energy, or has encountered circumstances which difficult this process tremendously.

The original author doesn't even have the source anymore, I don't think, and even if he did, he  isn't actively working on it right now. He has a habit of abandodning finished products, which TI-BOY is. It's finished. That isn't to say he might nto try to work on it again in the future.

Both of the reasons listed apply to this case. You don't need to read the bulk  of this, just the reasons I gave.