For the record the dry weight of me genset was 167# the rack itself was pretty sturdy and weighed 200#. In the end I figured I added 400# to the rear of the trailer.
I had to reload the cargo in my trailer to re-balance the load after the platform was installed.
While my set up turned out great. I do not recommend this mod for all RV's. Only those with a solid I-beam frames should consider adding that much weight to the rear. Even then reinforcement maybe required. I would certainly be sure a certified welder examined the entire frame before proceeding.
The real advantage of this set up is not having to load/unload or manhandle the genset. Because the genset was always there it was used more frequently. Lunch breaks and roadside stops always had electric and A/C. We could leave the dog in the RV with the A/C on.
You won't have to make any special accommodations for the genset.
Lastly the TT was always self contained. The truck could drive off but the genset always remained with the trailer in a secure place.