I tried the clone and clicking the button worked fine with the CSV you pasted.
I added a print("done") at the end of the running function and it successfully completed.
I didn’t try to follow the logic of the app.
You may have spotted the add_rows feature in accelerated tables which may speed things up.
The timeout for server functions is 30 seconds.
There is no timeout for client-side functions.
(if you want to do a long running client-side task (no server calls) then anvil-labs has client side background tasks)
A background task is probably the way to go if you’re getting close to the 30 second limit