I mean you could keep the project in a shared directory which you whole team can access via a network connection, but that can get very confusing with whos working on what and when so i dont recommend this.
Honestly i dont really understand what you expect - source control is by far the best way of tackling this and will be the most efficent way for you and your team going forward. Katalon already has built in Git integration which makes it even easier
Yea i think your right, there a ticket raised for this to be improved in the product but i dont think any action has been made on this by the looks of it. Maybe @Liam_B could give an update on whether or not this has progressed ?
Yea then i really dont have any sustainable ideas for you other than a shared directory of some sort. But this can cause mayjor issues in the long run. Maybe someone else will come along this thread and solve all ur issues