I'd say KISS certainly applies to architecture and design.
Over-architecture is a common problem in my experience, and there's a code smell that relates:
forced usage of overly complicated design patterns where simpler design would suffice.
If the use of a more advanced design pattern, paradigm, or architecture isn't appropriate for the scale of your project, don't force it.
You have to weigh the potential costs for the architecture against the potential savings... but also consider what the additional time savings will be for implementing it sooner rather than later.