I have also installed a couple of these units. The first one was in a 2001 Winnebago Adventurer, and the second one was in a 2013 Adventurer. Both on the Ford F53 chassis.
In both cases I ran the wiring and air hoses through the chassis manufacturers wire looms. It took a little longer to open them and insert the wires and tubing, but I knew there wouldn't be any interference or heat problems once the job was finished.
I wouldn't count deciding where to position things, or where to run the wiring as part of the job. If it was done by a professional they would have a set procedure and charge accordingly. Actual installation time on both Adventurers was about 10 hours each.
The 2013 took a little longer. Not because it was more difficult, but rather because that particular year Ford used hybrid brake lines. It took longer to install the proportioning valve and plumb it into the brake system. The brake lines had metric threads, but double flared ends like those used on SAE style brake lines. Standard metric fittings use a ball end. I didn't know they used this style brake fitting until I opened the lines, so everything came to a standstill until I found the proper fittings.
I had to order an adaptor from a company that specializes in brake systems for hot rods and race cars. Apparently mixing SAE and Metric fittings is common in this industry.
As previously mentioned there are many differences between brands of motorhomes. These differences can determine whether it takes 10 hours or 40 hours to install a braking system. This is also true with different toads. We picked a Jeep Wrangler because of it's simplicity and off road capabilities. There was no facia to remove, cut and reinstall, or need to be a contortionist. Everything was straight forward, easy to access, and relatively simple to install.
Installing the brake cylinder, break away switch and reservoir, and wiring the lights took about 4 hours.
2013 Adventurer 32H