From Sumit's note

‘So as to’ means ‘in order to’. Though it is not preferred in GMAT when ‘so that’ (with proper usage) is present, it is not a wrong conjunction per se. But note that split forms of ‘so as to’ & ‘so as not to’ are always wrong in GMAT.

From Beat the GMAT flashcards

So + ADJECTIVE + as to + VERB
- “Her debts are so extreme as to threaten
her company.” (Correct)
- “He exercises everyday so as to build his
stamina.” (Incorrect)

One is saying split forms are no go on GMAT while the other is saying split forms are ok.

Totally confused right now about "so as to". Any help is appreciated.