If he doesn't buy, or violates the terms of the agreement, he forfeits the option money.

If you do, you risk forfeiting your earnest money deposit.

Obviously if he does not pay, he has to be evicted and he will forfeit whatever you collected from him up front.

I Personally had some land under contract this past December/January but ended up forfeiting my deposit due to issues with the seller.

Having said that I don't think I have seen a situation where the other members forfeited their ownership.  

If they fail to sign the lease and start paying rent by (DATE), for any reason, then they will forfeit the entire deposit and the property is offered to the next person or goes back on the market. 

If they choose after 3 years not to buy it they will forfeit their 20% down and any update costsWhat's your thoughts?

It also stated that if the time expires before the list of items is finished and a building permit is obtained, the developer forfeits its rights to develop the properties.

Or do they forfeit the exchange benefit because they’re not purchasing as much as they sell?

But the reality is that the OP would be forfeiting a number of advantages by investing in TX, especially when there are markets within an hour or two drive that will likely allow her to still make a solid first investment.