Managing timeouts for Nginx and PHP

I would like the default timeout for my API to be 60 seconds. But for some endpoints I would like the flexibility to add a few seconds to the timeout duration.

I can do this in PHP like so – ini_set('max_execution_time', '120');.

So to achieve this I want to set Nginx timeout to 300 seconds (5 minutes) and as mentioned the default timeout for PHP to 60 seconds.

I was just wondering whether there are any dangerous downsides to this approach.