@Derek_Gervais @IAS @PeterTGIT
So in the end what I ended up using were webhooks. I passed a GET parameter with the landing page redirect and then the webhook posts the form data off to my php page which takes care of both POST and redirecting the user to the correct page. The only issue I find is that webhooks seem very slow to fire off. In the workflow I have it so that they fire any time the landing page’s form is submitted, but if the contact already exists it seems to be very hit and miss or it fires upto a minute later.
It would be great if Hubspot could just let you assign a webhook to a form without any conditionals because if I had to guess the workflow conditional checks are what’s slowing them up.
Anyway thanks for the suggestions guys, all worked out in the end.