Bjørn, I know you're hoping that your X delivery will be pretty quick - and maybe it will be.
Consider this:
A Founders X can be made at anytime - it's the VIN series (different than Signature or Production) and a few badges that make it a Founders. I suspect that the additional Founders will just be batched in with Signatures. Definitely if you have selected Sig Red, because after the last Signature, I'm sure they'd like to call that color 'done!' for awhile. If you weren't choosing Sig Red, it could be made a year from now, with a Founders VIN and bading.
I always thought it was brilliant that they made the prizes Founders. If it was a Signature, there would be people upset that the number of Signatures had increased. If it was Production, there would be people annoyed over line jumpers. But a Founders? No one is upset over that, except perhaps a few of the Founders who are watching the number increase.
I expect to see my Founders show up sometime during the Signature run.