Hi there @TheSuburbs,
Thanks for posting to the Community. Hope I can help with a solution to your question.
For some info:
Klaviyo's dynamic coupon codes will provide the same code in all emails of the Flow! As long as you refer to the same coupon in each flow, the code will be the same as long as the code is not expired. A new code would only be sent if the initial code expires. For example, using the same {% coupon_code 'Welcome10' %} tag in Emails 2 and 3, Klaviyo will automatically insert the same unique code that was previously issued to the recipient. The exception is if the code has already expired, in which case we will issue a new one. Unfortunately, Klaviyo does not track coupon redemption. Using a filter for a placed order event would be the best option.
For reference, this is explained here: Use Your Coupon in a Flow Email
If you use the same coupon tag within multiple flow messages, the recipient will receive the same unique code each time until the code expires.
Maybe an alternative you could try is to add a last step in Flow #1 of the sequence to update profile property to “has completed flow 1” and then you could have another flow that targets those with that property only. From there you could attach a new discount code.
I will investigate further and let you know what I come up as well,
Alex