Imagine if Google Maps was truly imperative and asks you to input the individual roads you want ahead of time - then it would not be useful.

I'd love to be able to have the ability to request specific roads in Google Maps directions, as it is you have to jury-rig imperative elements by adding waypoints at the start and end of the route you want included.

This illustrates me point: Systems for transforming declarations into imperative steps will always have limitations in terms of what can be declared and what states that can generate good imperative steps from/to. Once you step outside those limitations, you inevitably need to re-introduce some amount of your own imperative configuration. Ideally, eventually you make that imperative logic declaratively configurable and contribute that back to the commmunity.