Meaning of "so that"

Solution 1:

Firstly, the Employer will make a demand on the bank which provided the PB. For tactical reasons, this demand is often made [so that the bank has as little time as possible to inform the Contractor], and at an inconvenient time [so that the Contractor struggles to engage lawyers to prevent the bank from paying out on the Performance Bond].

Preliminary point: "so that" is not a syntactic unit, not a 'compound subordinator. The bracketed expressions are purpose adjuncts consisting of the preposition "so" followed by a declarative content clause as its complement.

Some older grammars claim that "so that" is a syntactic unit, a constituent, but this is wrong. It actually consists of the preposition "so" with a declarative content clause as its complement. We know this to be the case because the subordinator "that" is readily omissible.