I pointed out decades ago formal business plans kill new businesses.
What do successful startups do instead?
Rather than say they "experiment" with prospects I use the more common term "selling."
Successful business start by selling. The best thing to do to start a new business is to sell something to someone.
Selling is pay as you go market research, and it is much more accurate than a research interview. The question "would you buy this if we had it" and "will you give me a check for this now" are entirely different questions.
For more see my little book on Amazon "Daring Mighty Things-- The Simplest Way to Start Your First (or Next) New Business."
Triggered just now when I watched current conventional thinking about business startup: Google "osterwalder's business model canvas planning kills" there are several videos that make the same points.