Regarding work environment, while you may be familiar with this in a three-axis sense, you also must consider it in a five-axis sense.

Does the actual work envelop get smaller as the part or spindle rotates? Using one of your common milling tools installed in the spindle, measure the work envelop with the tool vertical, as well as with the tool inclined to the machine’s maximum value.
Different five-axis machines use different five-axis controllers. Some controllers work best when the part is mounted with the origin of the part at the exact intersection of the rotational axes. Some controllers favor using an inverse feedrate option.

Many five-axis controllers contain logic to know exactly where the tool center point is in relation to the part, no matter how many rotations have occurred, while it is in motion. This functionality is often referred to as rotational tool center point (RTCP). Many users find that using advanced RTCP functions makes the implementation of five-axis easie