No particular trigger for the main crashes I knew of, happened a few times long ago but had beaten the game - might just be a lot of inputs and happening when a bird delivers or a package to deliver arrives or payment comes in, something like that
Didn't seem to happen in the first half of the game much
Oh, and is the storage price still wrong? It would always charge you for the next level
Like it asks you for 5k, and takes 7.5k or whatever the next level is
Alongside the saves if it was going to happen- why not add some debug logs to help track down the crashes?
Was a good game from what I remember, a bit much having to do it all in one sitting, but good elsewise