Here's my opinion on it (and trust me I'm a die hard mcm fan).
Yes there is potential for the A series motor. But think of it this way, he's in the land of Oz and A series parts aint going to be easy to get hold of if something went bang. Where as with a jap engine and there are a ton of old hondas in Australia it's incredably cheap and easy to get hold of parts or even after market parts.
Another thing, nothing is really more reliable that modern day engines with multi point injection, ecu's and in this case individual coils. Plus we have all wanted a 5th gear in our mini's as one point or another lets be honest.
Also the time it took to do the build, it's in a garage with professionals of coarse they're gonna be able to do the work a lot faster than us on our drive ways. As well as parts of the series was filmed back in mid January.
And yes alot of cutting into the vehicle to do push the steering rack back which unfortunately the reason that has put me off dropping a B16 into mine
Sorry if the above sounds like a rant but just felt like posting :)