Timeout issue

The 30-second limit is usually a php setting, or something else on your server. The plugin actually adds 50 seconds to the php processing time with every image on a bulk-optimize, but otherwise, doesn’t do anything with timeouts.
To further clarify, the timeouts in php only take into account actual php code, so the optimizers don’t actually use ANY time themselves. However, many webhosts have limits set to how long a process can run, or how much cpu it can use, etc.