Dumping actions is limited to 64Kb. That is why you can only export so much then an error is generated. Complicated apps are more of an issue when it comes to long action sequences (I.e.: they sometimes cause ToolBook to crash) or they make hunting for problems when they occur more difficult.
You may want consider embedding applications inside each other. My
PowerPac Help API is an example of this. Several smaller applications that run inside of each other using field objects,
pgGotoURL(), and
pgExecuteRemote() to exchange data and to manipulate objects and run actions in separate application windows where necessary. This makes editing actions easier and you can isolate what your actions were designed to do more effectively down the road. Troubleshooting can be narrowed down to a module, instead of searching through one big application AND your action exporter will work again because the modules are never likely to grow out of control.
Downside of embedding is that load time will slow a bit, but the
PowerPac can be set up to share its JavaScript so at least that part is cached between applications. I don't think the slower performance is that bad though.