Irregardless of whether or not you're happy with the current or future offer, I would be very concerned about the management. Not being able to openly and hone

Irregardless of whether or not you're happy with the current or future offer, I would be very concerned about the management. Not being able to openly and honestly communicate the parameters of your deal, which is their responsibility if they're doing the hiring, is a very bad sign and doesn't bode well for the future of the company. Especially when they realise they've given you an incorrect deal, or a deal they can't do, or whatever - the solution is not to quietly update the contract and push it across the table and hope you don't notice. The solution is of course to sit down and openly discuss the situation to make sure everyone you understand exactly what is going on, and why, then allow you to make your decision based on this new information. If none of the founders are able to do this, or want to do this, this is a major red flag.