This limitation is the reason I stopped using Coda. The pushback I received from users was how this was normal in products like Airtable and it was a big red flag in Coda. The integration issues here requiring custom scripts, etc. to accomplish a function is just one of the issues I ran into with Coda. As I jumped in further, it had many limitations in regards to outside application integration within major products, authentication issues, etc. Like many products I have used, the product is pretty thin when you push it for application uses. Notion does basically everything Coda does with a much wider array of template, integrations and support.
IMO is not really an app builder but more of a Notion alternative.