Just another hint to get better looking large areas like you bridge work that is to stager the joints, this is a roof panel that I have just started to work on, it is 100mm x 210mm, it gives a stronger sheet and the joins become less obvious. This is one of my experiments, placed the tiles on my plate so there is a small gap between the fingers then feed a very thin slurry into the gap then close the gap, not much stays in the gap, will need a bit of a clean up though.
The other thing I tried this time was to taper the fingers so they all go home properly and they slide together easier.
I would say he is top of the class in what he does.Mig Jimenez, wow, that's what you call detail! That will take some time to absorb all he has on YouTube!
The weathering is quite nice, the use of many different types of materials to get the effect you want is good thinking.