I did read some of your conversation but well too much for my dyslexia to go trough
I did read what Silver suggest to you
But i wonder why not simply use different Storage for save slots?
You have saving and loading as simple as it gets
Which you most likely are able to do
NOW
In my post i save to Storage named Storage
Assuming you have 3 buttons (You could have as many as you want 3 is just for example) there where they have different colors
Now imagine for Red button i am saving to storage named Slot1
Now i copy paste that event and for when Blue button is clicked i save to storage named Slot2
And so go on
And now you only care about about what button is pressed and to what storage name you are saving (I think you could even go with different group names like Group1 and Group2 and so go on instead of storage with different name)
I would say it is a lot easier than managing actual slots via strings