**This is less useful than you think.**

You're describing parallelization of tasks to make everyone more efficient. However, most normal tasks, especially mental ones are not that easily parallelized. If you were familiar with Gantt charts you'd know why this entire exercise will be fruitless.

For the case of your example, animation rendering, it's just not worth it. An animation company is not going to spend several hundred thousand dollars just so it can try to coordinate computer resources with its duplicate company. The rendering time is not the bottleneck and if they're going to spend that kind of cash they could simply buy more servers or rent server time.

For mental tasks it's even worse. A human working on a problem is a very linear task. Think about any problem you've solved and I doubt you could have just as easily started anywhere in the problem and then combined the finished result. This about splitting up to write your question, could you have jumped in at any paragraph and submitted it to your other selves to form the complete question? Highly unlikely. 

How about a larger task? Consider a company working on producing a more efficient and less expensive portal. There are a few phases to go through to get it done. For instance: 

 1. Design
 2. Simulation
 3. Prototyping
 4. Testing
 5. Manufacturing

Those phases of the project can not be split up between identical companies across worlds. There is nothing to simulate until the design is complete, you can't test something that isn't built, and you can't start manufacturing until testing shows the device will work. Again, useless.