I applaud your creative thinking here.
But there are a few things to consider:
The minimum CL for an EXEC card is $5K. Even if you have enough CL on other Citi cards to move $5K to an EXEC app at Recon, if you want to apply for a second EXEC, you will not be able to move the CL on the first one below $5K while keeping it open. I don't know your personal situation, but I'm guessing you are going to run out of potential CL too fast to "iterate the churning process" for very long.
And if you make the $10K spend on the first EXEC in time to cancel and avoid the AF, that $5K CL is going to be locked up for some time, possibly as long as 6 months, before it will become available for a new app.
The way Citi has been setting the closing date so close to the app date for most people, your AF will probably be due too soon to both cancel the first card, and also move the full CL to a new EXEC app at Recon. Your AF will probably be due way before the 65 days are up.
The only way I can see to "iterate" EXEC after EXEC, is to pay the $450 AF (actually $250 after the statement credit), then cancel the first EXEC at Recon for the subsequent EXEC app, and move the entire $5K CL to the new EXEC. Citi might well allow you to do that, if you can afford it. Also assuming the offer stays live for some time. You might even be able to get your net costs down to $150 per card, if you can get a retention offer on each card before you cancel it.
Be very aware all of this is YMMV !
Finally, maybe someone more knowledgeable than me can comment on the likelihood of someone being approved for an EXEC card, 8 days after only being offered a $1K CL on a regular AA card....