I am suggesting you could demonstrate that your ethics are beyond question.
Do you put your pride above scientific discovery? Suppose you were to die tomorrow? A piece of knowledge would be lost to humanity.
I saw your offer.
Your suggestion that they should pay half your proposed considerable travel expenses is sufficient disincentive to suggest to me that the offer was not seen as being made in good faith. I wouldn't have considered it for a minute. Why do a test you know the result of when you can brush the guy off because he can be seen to be making unreasonable financial demands?
In any case, you cannot be seen to profit from the exercise in any way, shape or form. You cannot be said to have made an open offer with this financial entanglement, be it so trivial as half the price of a trip to Florida. Try asking to meet halfway. Ask a university or college for help. If the negotiation stalls again, come back and ask me for more suggestions, but not before exercising some of your own ingenuity, please.
You were also suggesting that you could use your own laptop AFAICS. Surely you understand that this is absolutely out of the question, to exclude the possibility of tampering.
When it comes right down to it, there are no "gentlemen's agreements" in such circumstances.
It's the implicit failure to recognize this, however, that redounds most to your discredit. Of course it's not going to be done with your equipment. That's the first thing any nay-sayers are going to question if you get a positive result. You should know that.
The whole point is to make it so that you can't cheat. Then there is no issue of trust.
So set it up without any financial penalties on the opposition and there's no arguing about the firmware. Jeez. Anybody'd think it was difficult to prove one way or the other, but if you spend your time arguing on the internet it'll go on for ever. If it goes on forever though, you'll be discredited by default.
The measures taken are for your protection too. They make the results less controversial and more likely to gain acceptance.
Why should I believe in your ethics? Isn't it rather brazen to accuse the founder of a web site, on his very own website, of being unethical? Are you a troll?