Prorated Movement

There is no mention in Impetus of prorating movement when moving from one terrain type to another. So imagine an FP moving from difficult into normal terrain. Assume that it manages to exit the difficult terrain in 1.5U which would mean that it has 2U left. My understanding is that the FP's total move is nonetheless 3U in this situation. Is that correct?

How would one handle a situation where a CL is evading back into difficult terrain? Say that is moves 8U back and touches difficult terrain. My initial instinct is to say that the CL cannot evade in this circumstance because it cannot move its full move distance. Is this correct? CL could evade back into/through broken terrain but it would become immediately disordered. Does that sound correct?