Then understanding about Suddhāṭṭhaka is not that important for progress on the path, right?
The higher entity is bhūta. The manual from Bhikkhu Bodhi starts with bhūta. I do not find the word suddhāṭṭhaka (the search function does not properly work in the pdf). I guess the bhūta element is in the Tipitaka?
A Quest to Recover Buddha's True Teachings