Each On-Boarding Flow would have its own invite link. This would be a seemingly simple solution that would give the trainer more variety of On-Boarding Flows. We use Circle as a community app where I am able to create customized invite links for all sorts of offers and it is so easy.
For Example: We have a 6 Week Challenge and a 6 Month Program that have different Autoflows and On-Boarding Forms. Having a customized invite link for each would make the on-baording process seamless for both.