Hey @jeremyf - thanks for getting in touch. You're totally correct that scripts are able to be supported through custom apps that generate checkouts, so this is something I'd be happy to look more in depth into with you on our end.
I can't say for sure what could be causing the scripts not to trigger at the moment, but I can say that after checking with our development team, the issue could potentially be related to some updates that are currently being made to the checkout process as a whole.
You mentioned in your post that you tried creating some checkouts using the Checkout/Cart API and that the scripts didn't seem to trigger there either? Would you be able to share some information on some recent API calls (made within the last 14 days - which is our current log retention limit)? If you can share a call's payload body and some response information, like the Request ID from the response header, that would be great as a staring point and I'd be happy to dig into this further with you.
Let me know if I can clarify anything on our end - you can also reach out through our issue reporting forum if you'd prefer assistance over email. I also just wanted to thank you for your patience here too - I know it's been about a month since you reached out, so hope to hear back from you soon so we can keep looking into this.
Cheers!
