I've always preferred the stiffer webbing. Over the last 12 years, I've built around 100 BPW systems, and the stiffer webbing for me is no harder to set up.
There are little tricks I've picked up over that time, and using triglides that are made for double-thickness webbing is one that greatly helps with setup.
These are our wide slot slider with no teeth for 2" inch webbing Made to fit 2" / 50mm webbing You can fit either 1 or 2 pieces of webbing through this slot 2 1/4" inch Long 1" inch Wide 1/8" Thick for strength and durability Made out of marine grade 304 stainless We tumble these for 48 hours...
www.piranhadivemfg.com
Once they are on there they are just as secure and lay as flat as standard ones. The stiffer webbing also makes donning and doffing easier in and out of the water because it doesn't flop around like a wet noodle.
Also, having a good set of pliers on hand and trimming the ends just a tad to make them rounded or triangle-shaped works well.
After trimming any webbing, a lighter or mini torch is essential to singe the ends immediately.
I learned a lot in the beginning, setting up the old DSS plates with the inserts in the webbing slots.
Then even more when I started to do custom setups with different color webbing and hardware that I made for people who were oddly shaped and the basic harness was just not as comfortable for them as an "H" style with a chest strap. Some of that hardware was modified and is used on the HOG TBCS harness when I was helping with the design of that.
Piranha has a lot of options to customize a harness. Including webbing in different colors and hardware to get it exactly the way you want it.