How to interpret each word in "so as to" separately?

I already know the whole phrase so as to means in order to.
but still a bit curious about how to interpret each word in this phrase separately.

can I interpret the following sentence like this?

He sat at the front so as to be able to hear. (quoted from cambridge dictionary)

where
so = in such way;

as = because of that;

to-clause is reduced from the clause with a modal auxiliary i.e. he will/would be able to hear,

to here is implying the meaning of mood auxiliary will/would.

put all together, the whole sentence can be interpreted like this:

He sat at the front in such way because of that he would be able to
hear.

not sure I get it right.