As soon as you get the error after pressing add to cart refresh the page.
I normally have 5 tabs open per bundle I want and repeat the above process.
With Firefox & Chrome you can click on the first tab, hold command (shift on windows) then click the last tab and press command (shift on windows) + r to refresh all tabs at the same time.
After they all refresh click add to cart on each tab, repeat the process until you get a captcha, then proceed to checkout.
After you check out go to the next tab and repeat to the process to get another console on the same drop.