First of, welcome to our Protege community.
You can swap any engine in there you want, provided you have plenty of time and money. The reason why people are swapping the BP engine to replace Z5 is because it is the most efficient way to do it. It is already a major pain in the *** to do in the first place, so just the thought of swapping anything else but BP is not a good idea. Search on this forum, or here
. Some people already have done either BP or BPT swaps. So, you have a lot of resources to look into in order to save yourself some time and money. Because you will need it.