An agent who is willing to have their name connected with "JellyBean" will quickly find themselves in the outer darkness, unable to understand why their emails are not read and every call goes to voice mail.
When that agents name is associated with unqualified buyers, assigned contracts and rogue investors, this, in capital letters is TROUBLE for everyone involved. I've observed JellyBean buyers jump out of the agent car as it rolling down the drive to run to the homeowner, push a card in their hand and say, "Call me, we can get a better deal." That agents name has long since evaporated from the list of active agents. He got associated with a JELLYBEAN.
As a listing agent, I place on the market homes that can be sold by those who are able to sell.
A buyer agent is responsible for presenting those who have a documented ability to buy and the conditions required for such a purchase. No one wants their time wasted by an investor type who is following the 40 to 1 scheme taught in those seminars. Now, if you offered the responding agent $50 bucks for every offer submitted, you wouldn't be a total JellyBean just a regular jellybean.
If I were the Seller's Agent, I would advise my Seller not to accept your offer. In this day and age,, loan officers work on weekends. There is no reason why you can't obtain a written pre-approval, unless you can't meet the requirements for the loan you need. Most buyers obtain a loan pre-approval before they start looking for a home. (If you are paying for a home with cash, then you need written proof of funds from your banker.)
Unfortunately, even if you can find an agent willing to submit your over with out a traditional pre-approval letter, you'll be hard pressed to find a selling agent that will entertain your offer, let alone seriously consider it, without a pre-approval letter or proof of funds.