Sorry, I'm a bit confused by your query? Are you dealing with a mixture (where the constraint is due to the fact that when you choose levels for one factor it affects the levels for the other factor as both factors sum to 1)? If you are running an experiment, you, obviously, choose the levels you set. Having F1 at levels: -1 = 250 and 1 = 350 and F2 levels at: -1 = 100 and 1 = 200 easily meets your criteria.
If you have JMP Pro you can use the Disallowed Combinations Filter to specify that. Remember that you're specifying combinations of factors that are disallowed. So you need to specify (X1 is in the range below 2 AND X2 is in the range 2 to 3) OR (X1 is in the range 1 to 2 AND X3 is in the range above 2). As shown here: