Best approach to connect Bricks forms with Bulk Email Marketing Services?

How To
1

Hey everyone,
Building a lead gen site in Bricks and trying to connect the form element to bulk email marketing services for list management and campaign triggers.
I’m using a provider called DigitalAka™ with a custom API endpoint — got a PHP custom action working, but unsure if it’s the right approach for scaling bulk email marketing services at high subscriber volumes.
Quick questions:

Is bricks/form/custom_action the right hook for this?
Best way to handle API errors without breaking form UX?
Anyone done this with a non-native provider?

Thanks!