I'm going to piggy back on this so if you find the most accurate answer, I'd like to know too.
In my attempt to help, one of the most helpful books for writing (traditional fiction/nonfiction) is "Self-Editing for Fiction Writers" - the maxim, "Show, don't tell" is the central theme and what I would recommend you consider, but tailor it to a technical aspect. Here's an example of telling vs showing -
That night, the father was very nervous while he waited while he waited for his daughter.
VS
He checked his watch. 1:03 a.m. The father noted his nail was almost chewed to the nub. He got up and walked to the window and peered out. He checked his watch again, still chewing on his raw finger. It was still 1:03 a.m.
See the difference? Showing typically takes more effort and time which makes it challenge for engineer-types whose livelihood often depends on efficiency and saving time. But the result is more powerful as you begin to empathize with the character.
I struggle with technical writing too so the only other advice I could add is to get OTHER eyes on your writing as much as possible, that fresh perspective is invaluable.
Also, amazon mturk has surveys that you can have strangers do quick surveys for like 25-50 cents a head (it's mercenary work so the survey needs to be quick)... but you can consider using it if you want to test clarity in your message - mind you, these will NOT be investors but if you are trying to explain a technical concept to outsiders, (investors probably won't understand why your pitch is so important) then chances are if you get 50 strangers on the internet to all understand your technical statement, you are probably in good shape.