Well made though, and TBH all of these types of bikes are very low production numbers. How many allez does Specialized's manufacturer knock out for them every year, 80k, 100k, 150k?
Loads of DIY solutions online, just got to figure how much your own time is vs buying ready to go. Some DIY solutions are excellent, as you say depends how much engineering you want to put in, always terrified when I see people walking out of halfords/evans/decathlon with a child seat that they will fit themselves, probably with a zip tie and an adjustable!
R+M are much heavier, but for more sedate non bikey people, the front forks have problems with wear and then corrosion, they might have fixed it for 2020MY. Also Bosch have a new 'cargo bike' specific motor out for 2020 which I imagine will be found on a lot of R+M products which if your thinking of one, maybe hold out until then ;)