Data Action API 429s during bulk record creation in Architect

Trying to understand the rate limiting behavior for custom Data Actions when invoked via Architect flows.

We are hitting 429 Too Many Requests errors on POST /api/v2/data/actions/:id when processing batches larger than 500 records. The integration uses multi-org OAuth with a dedicated app token.

Is there a documented burst limit for Data Actions specifically, or should we implement client-side throttling? The standard Platform API limits do not seem to apply here.