Use 'so far' to indicate progress made over a time period in a larger process or goal.

Progress Tracking

'So far' suggests that situations may change and more developments are possible.

Evolving Situations

It can be used to express that what has happened meets or differs from what was expected.

It implies that while some progress or extent is possible, there are limits to what can be achieved.

'So far' can indicate that resources such as time, money, or energy have their limits.

Speaks to how much one can endure before reaching a limit.