A cardinal sin in the management of a patent portfolio is to lose track of what's covered by a patent and the commercialised product. In their enthusiasm to file a patent application, inventors often lose sight of the need to ensure that the invention is capable of being designed for manufacture.
It is usually the manufactured product that is copied.
You need to bear in mind that an infringer will more than likely be copying your manufactured product. Your ability to enforce your patent rights could be severely restricted if your patent is not accurately aligned with the product. So you should at least be satisfied that the material you are presenting to your patent attorney is capable of being manufactured at an acceptable price.
Investors like to consider a commercial-ready package
I always enjoy chatting to clients about their business plans for the invention. In my experience, it is very difficult, if not impossible, for an inventor to generate any sort of investor interest without a commercial-ready package. By that I mean a design for manufacture, details of the cost of manufacture, sale price, distribution channels and at least tentative orders. In other words, an actual business that can be sold. Of course, it may not be your long-term goal to build a company that sells widgets. But you can't expect an investor to be interested in an invention that is completely untested.
Of course, not all inventions are the same. It may be necessary to file a patent application with some level of ignorance of all the commercial aspects. But you should do your best to satisfy yourself that the patent application covers a product that is as commercial-ready as possible.